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Instruments is a performance-analysis and testing tool for iOS, iPadOS, watchOS, tvOS, and macOS apps.

Instruments Documentation

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Request for clarification / Documentation Feedback
Dear Apple Developer Support team, I would like to request an official confirmation regarding the handling of transaction status in the App Store Server API, specifically for the GET /inApps/v1/transactions/{transactionId} endpoint. As per our current understanding from the official documentation (Get Transaction Info), the API’s behavior appears to be: If a transaction is finalized and successfully processed by App Store, querying this API will return HTTP 200 OK along with transaction details. If a transaction is still in a pending or deferred state (such as awaiting Ask to Buy approval or pending authorization), the API will not return a 200, and instead respond with HTTP 404 Not Found or an appropriate error. Could you please confirm if this behavior is accurate and officially supported? Specifically: Does a 200 OK response guarantee that a transaction is finalized and successfully recorded on App Store servers? In cases where a transaction is pending approval (e.g. Ask to Buy), is it correct that GET /transactions/{transactionId} would return 404 Not Found until the transaction is finalized? We would greatly appreciate your confirmation to align our server-side logic for transaction validation accordingly. Thank you very much for your support! Kind regards, cuongnx
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256
Jun ’25
Datadog Mobile Vitals equivalent in Instruments
Hello We use Datadog Mobile Vitals in our app and I'm trying to run some tools in Instruments for comparison. I'm not sure what tool should I use for some of those metrics: Slow Renders Description: With slow renders data, you can monitor which views are taking longer than 16ms or 60Hz to render. Instruments equivalent: Hangs including microhangs (?) CPU ticks per second Description: RUM tracks CPU ticks per second for each view and the CPU utilization over the course of a session. The recommended range is <40 for good and <80 for moderate. Instruments equivalent: CPU Profiler (?) Frozen Frames - Description: Frames that take longer than 700ms to render appear as stuck and unresponsive in your application. These are classified as frozen frames. Instruments equivalent: Hangs with > 500ms (?) Memory Utilization Description: The amount of physical memory used by your application in bytes for each view, over the course of a session. The recommended range is <200MB for good and <400MB for moderate. Instruments equivalent: Allocation (?)
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314
Jul ’25
How to export Allocations report in XML (Call Tree format) with xctrace?
Hello Apple team, I am using xctrace to record an Allocations trace on iOS. For example: xctrace record --template "Allocations" --launch com.example.myapp --time-limit 30s --output alloc.trace After recording, I can export the results in Allocations List format (flat list of allocations) using: xcrun xctrace export --input ./alloc.trace --xpath '/trace-toc/run/tracks/track[@name="Allocations"]/details/detail[@name="Allocations List"]' --output ./alloc.xml This works fine and produces an XML output. However, what I really need is to export the data in Call Tree format (as shown in Instruments GUI). I checked xctrace export --help, but it seems that the Allocations template only supports the List view for export, not the Call Tree breakdown. My question is: 👉 Is there a way to export an Allocations trace in XML with Call Tree details using xctrace? 👉 If not, is there an API or recommended workflow to automate this instead of exporting manually from Instruments GUI? Thanks in advance for your help!
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365
Sep ’25
Battery Consumption Analysis Using Xcode Instruments
I have been working on battery consumption analysis for my application, and as part of this effort, I wanted to understand how competitor apps behave under similar usage conditions. To do this, I downloaded competitor apps from the App Store and attached them to Instruments via Xcode. I then executed a defined set of manual test scenarios to simulate real user behavior. During these tests, the iPhone was connected to a Mac and charging continuously, which meant that System Power Usage logs were not generated in Instruments. However, I was able to capture detailed metrics such as: Network usage CPU load GPU activity Display and brightness impact Other runtime performance characteristics Since direct battery drain data was unavailable, I used derived analysis (with AI assistance) to estimate approximate power consumption based on the above metrics, assuming real-device (battery-powered) conditions. According to Apple documentation, System Power Usage in Instruments is not directly tied to the device’s battery percentage. Instead, it appears to be computed using contributing factors such as CPU, network, display, and other subsystem activity. This raises a few important questions about data reliability and methodology. Key questions: How reliable are Instruments-based metrics (CPU, network, display, GPU) for estimating real-world battery consumption when the device is charging? Can these metrics be safely used as a comparative baseline between competitor applications, even if absolute battery drain values are unavailable? Is the System Power Usage instrument essentially a derived model based on subsystem activity, and if so, does it remain accurate when the device is not discharging? From Apple’s perspective, is this a valid approach for relative power comparison, provided that: The same device is used OS version is identical Test scenarios are consistent and repeatable Based on these findings, would it be reasonable to proceed with instrumenting our own application, run the same scenarios, and draw conclusions using relative comparisons rather than absolute battery percentages? The intent is not to claim exact battery drain numbers, but to establish a directionally correct and repeatable comparison that can guide performance optimizations in our own application. I would like to understand whether this methodology aligns with Apple’s recommended practices, or if there are limitations or inaccuracies I should be aware of before relying on these results for decision-making.
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531
Jan ’26
The best way to build, test and upload an iOS app without owning a Mac
Hi everyone, I’m developing a cross-platform mobile app (React Native) but I don’t currently own a Mac. What is the most reliable and professional way to: Build the iOS version Test it properly (real device / TestFlight) Upload it to the App Store Are cloud Mac services (like MacinCloud, AWS Mac, etc.) considered stable for production release workflows? Is there any fully supported workflow without direct access to a physical Mac? Would appreciate real-world experience from developers who faced the same situation. Thanks in advance.
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244
Feb ’26
Is dtrace & dtruss supported on current macOS?
When I try to run dtruss on a command line program (freshclam) I see: $ sudo dtruss -a /usr/local/bin/freshclam 2>&1 | tee ~/tmp/dtruss.out dtrace: system integrity protection is on, some features will not be available dtrace: failed to execute /usr/local/bin/freshclam: DTrace cannot instrument translated processes I did some research and found advice on how to enable dtrace use via running: csrutil enable --without dtrace in a terminal running in macOS recovery mode. When I do that I see a warning saying this is an unsupported configuration and that it will allow unsigned kernel modules to be loaded. This is not what I want, I just want to run dtruss on a program while keeping all the other SIP protections in place. Why can't I just use sudo to grant the privileges for dtrace to work? All of this has me wondering if Apple intends for developers to use dtruss/dtrace in the current macOS?
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179
Feb ’26
How to programmatically determine fixed CPU frequency for memory latency benchmarking on Apple Silicon?
Hi everyone, I am developing a benchmarking tool to measure memory latency (L1/L2/DRAM) on Apple Silicon. I am currently using Xcode Instruments (CPU Counters) to validate my results. In my latest run for a 128 MB buffer with random access, Instruments shows: Latency (cycles): ~259 cycles (derived from LDST_UNIT_OLD_L1D_CACHE_MISS / L1D_CACHE_MISS_LD). Manual Timer Result: ~80 ns. To correlate these two values, I need the exact CPU Frequency (GHz) at the time of the sample. My Questions: Is there a recommended way to programmatically fetch the current frequency of the Performance cores (p-cores) during a benchmark run? Does Apple provide a "nominal" frequency value for M-series chips that we should use for cycle-to-nanosecond conversions? In Instruments, is there a hidden counter or "Average Frequency" metric that I can enable to avoid manual math? Hardware/Software Environment: Tool: Instruments 26.3+ (CPU Counters Template). Chip: A19, iPhone 17 pro. OS: 26.3.
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541
Mar ’26
Subject: [SDK / Instruments] Clarification on Runnable & Blocked Time Semantics — Customers Misinterpreting as CPU Usage
Subject: [SDK / Instruments] Clarification on Runnable & Blocked Time Semantics — Customers Misinterpreting as CPU Usage Hi Apple Developer Technical Support Team, I hope this message finds you well. I am writing to seek urgent clarification on a profiling question that is directly impacting our SDK customers. Context We provide an iOS SDK that is integrated into third-party applications. Our SDK includes a background monitoring thread created via: -[NSObject performSelectorInBackground:withObject:] As documented, threads created through this API carry a default (relatively low) scheduling priority. Inside the thread, we call sleep(1) once per second for periodic idle intervals, and we collect CPU usage metrics using kernel APIs: • task_threads() • thread_info() Both calls involve kernel-level operations and are known to trigger context switches internally. The Core Issue — Customer Misinterpretation When our customers profile their apps using Instruments with "Context Switch Sampling" enabled, they observe that our SDK thread shows a large proportion of time labeled as "Runnable" and "Blocked". A representative example: • Total (wall clock): 4.30 s — 100% • Runnable: 3.06 s — 71.4% ← customers flag this as high CPU usage • Blocked: 1.05 s — 24.5% • Running: 176 ms — 4.1% ⚠️ Our customers are interpreting the "Runnable" time (71.4%) as CPU consumption by our SDK, and are raising concerns that our SDK is degrading their app's performance. We strongly believe this interpretation is incorrect — a thread in the "Runnable" state is merely waiting in the scheduler's ready queue and has NOT been assigned to any CPU core, therefore it should NOT consume any CPU resources. However, we need an official confirmation from Apple to address our customers' concerns definitively. Our Questions Do the time values shown next to "Runnable" and "Blocked" in the Time Profiler call tree represent wall-clock waiting time (i.e., time spent in that state), or actual CPU consumption time? Does a thread in the "Runnable" state consume any CPU resources on the device? We want to confirm clearly: does Runnable time contribute to CPU load or battery drain in any way? Is it correct that the high Runnable time observed is caused by the combination of: a. The low thread scheduling priority assigned by performSelectorInBackground:withObject:, and b. Context switch overhead introduced by the task_threads() and thread_info() kernel calls? Is there any official Apple documentation that explicitly describes the semantics of "Runnable" and "Blocked" time in Instruments, which we could reference when communicating with our customers? An authoritative answer from Apple would allow us to accurately explain the profiling data to our customers and clarify that the high "Runnable" time does NOT represent CPU consumption by our SDK. Thank you very much for your time and support. Best regards
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108
Apr ’26
[SDK / Instruments] Clarification on Runnable & Blocked Time Semantics — Customers Misinterpreting as CPU Usage
Hi Apple Developer Technical Support Team, I hope this message finds you well. I am writing to seek urgent clarification on a profiling question that is directly impacting our SDK customers. Context We provide an iOS SDK that is integrated into third-party applications. Our SDK includes a background monitoring thread created via: -[NSObject performSelectorInBackground:withObject:] As documented, threads created through this API carry a default (relatively low) scheduling priority. Inside the thread, we call sleep(1) once per second for periodic idle intervals, and we collect CPU usage metrics using kernel APIs: • task_threads() • thread_info() Both calls involve kernel-level operations and are known to trigger context switches internally. The Core Issue — Customer Misinterpretation When our customers profile their apps using Instruments with "Context Switch Sampling" enabled, they observe that our SDK thread shows a large proportion of time labeled as "Runnable" and "Blocked". A representative example: • Total (wall clock): 4.30 s — 100% • Runnable: 3.06 s — 71.4% ← customers flag this as high CPU usage • Blocked: 1.05 s — 24.5% • Running: 176 ms — 4.1% ⚠️ Our customers are interpreting the "Runnable" time (71.4%) as CPU consumption by our SDK, and are raising concerns that our SDK is degrading their app's performance. We strongly believe this interpretation is incorrect — a thread in the "Runnable" state is merely waiting in the scheduler's ready queue and has NOT been assigned to any CPU core, therefore it should NOT consume any CPU resources. However, we need an official confirmation from Apple to address our customers' concerns definitively. Our Questions Do the time values shown next to "Runnable" and "Blocked" in the Time Profiler call tree represent wall-clock waiting time (i.e., time spent in that state), or actual CPU consumption time? Does a thread in the "Runnable" state consume any CPU resources on the device? We want to confirm clearly: does Runnable time contribute to CPU load or battery drain in any way? Is it correct that the high Runnable time observed is caused by the combination of: a. The low thread scheduling priority assigned by performSelectorInBackground:withObject:, and b. Context switch overhead introduced by the task_threads() and thread_info() kernel calls? Is there any official Apple documentation that explicitly describes the semantics of "Runnable" and "Blocked" time in Instruments, which we could reference when communicating with our customers? An authoritative answer from Apple would allow us to accurately explain the profiling data to our customers and clarify that the high "Runnable" time does NOT represent CPU consumption by our SDK. Thank you very much for your time and support. Best regards
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188
Apr ’26
[SDK / Instruments] Clarification on Runnable & Blocked Time Semantics — Customers Misinterpreting as CPU Usage
Hi Apple Developer Technical Support Team, I hope this message finds you well. I am writing to seek urgent clarification on a profiling question that is directly impacting our SDK customers. Context We provide an iOS SDK that is integrated into third-party applications. Our SDK includes a background monitoring thread created via: -[NSObject performSelectorInBackground:withObject:] As documented, threads created through this API carry a default (relatively low) scheduling priority. Inside the thread, we call sleep(1) once per second for periodic idle intervals, and we collect CPU usage metrics using kernel APIs: • task_threads() • thread_info() Both calls involve kernel-level operations and are known to trigger context switches internally. The Core Issue — Customer Misinterpretation When our customers profile their apps using Instruments with "Context Switch Sampling" enabled, they observe that our SDK thread shows a large proportion of time labeled as "Runnable" and "Blocked". A representative example: • Total (wall clock): 4.30 s — 100% • Runnable: 3.06 s — 71.4% ← customers flag this as high CPU usage • Blocked: 1.05 s — 24.5% • Running: 176 ms — 4.1% ⚠️ Our customers are interpreting the "Runnable" time (71.4%) as CPU consumption by our SDK, and are raising concerns that our SDK is degrading their app's performance. We strongly believe this interpretation is incorrect — a thread in the "Runnable" state is merely waiting in the scheduler's ready queue and has NOT been assigned to any CPU core, therefore it should NOT consume any CPU resources. However, we need an official confirmation from Apple to address our customers' concerns definitively. Our Questions Do the time values shown next to "Runnable" and "Blocked" in the Time Profiler call tree represent wall-clock waiting time (i.e., time spent in that state), or actual CPU consumption time? Does a thread in the "Runnable" state consume any CPU resources on the device? We want to confirm clearly: does Runnable time contribute to CPU load or battery drain in any way? Is it correct that the high Runnable time observed is caused by the combination of: a. The low thread scheduling priority assigned by performSelectorInBackground:withObject:, and b. Context switch overhead introduced by the task_threads() and thread_info() kernel calls? Is there any official Apple documentation that explicitly describes the semantics of "Runnable" and "Blocked" time in Instruments, which we could reference when communicating with our customers? An authoritative answer from Apple would allow us to accurately explain the profiling data to our customers and clarify that the high "Runnable" time does NOT represent CPU consumption by our SDK. Thank you very much for your time and support. Best regards
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88
Apr ’26
APU H series
What about a studio rendering audio interface with airpods max, when linked has a usb-c*thunderbolt's cable. Them can bring Use and Space at utility. +can bring 32 bits dept into sound edit +can bring Audio Spatialisation +and a bunch of codecs to encode ogg capabilties or atmos/dtsX fidelity -since the latency became minimalist at bluetooth 6.0, a think could look forward about cableless capability upforth.
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3w
(iOS 26) - PowerProfiler trace file cannot be opened
I kept CoreLocation’s startUpdatingLocation running for a full day and used Performance trace - PowerProfiler to track the power usage during that time. The trace file was successfully generated on the iOS device, and I later transferred it to my MacBook. However, when I tried to open the .atrc file, I received the following warning: The document cannot be imported because of an error: File ‘/Users/jun/Downloads/PowerProfiler_25-06-16_181049_to_25-06-17_091037_001.atrc’ doesn’t contain any events. Why is this happening? Is there a known issue with PowerProfiler in iOS 26, or am I missing something in the tracing setup? Note: The .aar file and the extracted .atrc file are not attached here, as forum uploads do not support these formats.
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352
Jun ’25
Bottleneck analysis is not available in my Instruments
Hello, I wanted to try new Bottleneck analysis mode showcased in recent Apple's video, however when I select CPU Counters template in Instruments, there's no such option - just the same old "sample by Time/Events". I have the latest XCode 16.4 and OS Sonoma 15.5, the system is M4 Max. While Instruments shows version 16.0 in About dialog for some reason (a bug?), it definitely comes from the Xcode 16.4 package and the build id is the same (16F6) as for XCode 16.4. I also checked just in case on another M1 system (all updated as well) and it's all the same. Any clues why Bottleneck analysis is missing? Regards, Maxim
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272
Jul ’25
Question about Metrics Analysis in Xcode 26
Hello, I have recently been using the new Power Profiler tool introduced in Xcode 26 to analyze the power consumption of my app. My app primarily operates in the background. During a profiling session of 5 hours and 30 minutes, I observed that the app was active in the background for 2 hours and 30 minutes, while it remained in a suspended state for the remaining 3 hours. While the Power Profiler allows me to identify spikes in CPU, networking, and other resource usage at specific points, it is difficult to determine whether these values are objectively considered high. For example, in my case, the total QoS Execution Time of CPU Impact recorded during the 5 hours and 30 minutes was 12.18 seconds. I am wondering whether this is considered a good metric. Could you please advise on the following points? 1. Is there a commonly accepted or recommended ratio between app active time and CPU time that developers should aim for? 2. Are there any guidelines or reference materials on how to interpret CPU usage and other resource metrics for apps that primarily run in the background? Any insights or advice would be greatly appreciated. Thank you.
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316
Aug ’25
Complete control flow trace... possible?
Is there an xctrace instrument capable of capturing the complete control flow of a process? So far the best I can find is high-frequency sampling, but what I need is a trace of all machine instructions executed. This is easily done on Linux/Intel using the perf tool, which provides access to Intel's hardware-assisted tracing module (ptrace). According to the arm specification, my mac mini M1 (armv8.4-a) and M4 (armv9.2-a) both have hardware support in the CoreSight ETM (embedded trace macrocell) for full instruction tracing (i.e., no sampling, no gaps, no statistics--capturing the complete execution path). But it's not clear how I can access these features, if they are supported by the macos XNU kernel at all. After hours of searching online, it's nothing but dead ends. Any suggestions for documentation or Xcode tools or open-source tools or built-in macos tools would be much appreciated!
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262
Aug ’25
Instruments: GPU Service reported error: Selected counter profile is not supported on target device`
I could use the Metal System Trace before the most recent update, but now whenever I try to profile using the Metal Counter instrument, I get the [Warning] GPU Service reported error: Selected counter profile is not supported on target device. What is the issue here?
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0
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1
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196
Activity
Jun ’25
iOS 26 - SubscriptionOfferView & StoreView- memory leak
It seems as though using any initializer of SubscriptionOfferView or StoreView will create a memory leak. This can be simply reproduced by adding this to your SwiftUI view: SubscriptionOfferView(groupID: "yourgroupID", visibleRelationship: .all, useAppIcon: true) or StoreView(ids: ["monthly", "yearly"]) Tested on iOS 26 beta 2
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0
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0
Views
335
Activity
Jun ’25
Request for clarification / Documentation Feedback
Dear Apple Developer Support team, I would like to request an official confirmation regarding the handling of transaction status in the App Store Server API, specifically for the GET /inApps/v1/transactions/{transactionId} endpoint. As per our current understanding from the official documentation (Get Transaction Info), the API’s behavior appears to be: If a transaction is finalized and successfully processed by App Store, querying this API will return HTTP 200 OK along with transaction details. If a transaction is still in a pending or deferred state (such as awaiting Ask to Buy approval or pending authorization), the API will not return a 200, and instead respond with HTTP 404 Not Found or an appropriate error. Could you please confirm if this behavior is accurate and officially supported? Specifically: Does a 200 OK response guarantee that a transaction is finalized and successfully recorded on App Store servers? In cases where a transaction is pending approval (e.g. Ask to Buy), is it correct that GET /transactions/{transactionId} would return 404 Not Found until the transaction is finalized? We would greatly appreciate your confirmation to align our server-side logic for transaction validation accordingly. Thank you very much for your support! Kind regards, cuongnx
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0
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0
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256
Activity
Jun ’25
Datadog Mobile Vitals equivalent in Instruments
Hello We use Datadog Mobile Vitals in our app and I'm trying to run some tools in Instruments for comparison. I'm not sure what tool should I use for some of those metrics: Slow Renders Description: With slow renders data, you can monitor which views are taking longer than 16ms or 60Hz to render. Instruments equivalent: Hangs including microhangs (?) CPU ticks per second Description: RUM tracks CPU ticks per second for each view and the CPU utilization over the course of a session. The recommended range is <40 for good and <80 for moderate. Instruments equivalent: CPU Profiler (?) Frozen Frames - Description: Frames that take longer than 700ms to render appear as stuck and unresponsive in your application. These are classified as frozen frames. Instruments equivalent: Hangs with > 500ms (?) Memory Utilization Description: The amount of physical memory used by your application in bytes for each view, over the course of a session. The recommended range is <200MB for good and <400MB for moderate. Instruments equivalent: Allocation (?)
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0
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0
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314
Activity
Jul ’25
How to export Allocations report in XML (Call Tree format) with xctrace?
Hello Apple team, I am using xctrace to record an Allocations trace on iOS. For example: xctrace record --template "Allocations" --launch com.example.myapp --time-limit 30s --output alloc.trace After recording, I can export the results in Allocations List format (flat list of allocations) using: xcrun xctrace export --input ./alloc.trace --xpath '/trace-toc/run/tracks/track[@name="Allocations"]/details/detail[@name="Allocations List"]' --output ./alloc.xml This works fine and produces an XML output. However, what I really need is to export the data in Call Tree format (as shown in Instruments GUI). I checked xctrace export --help, but it seems that the Allocations template only supports the List view for export, not the Call Tree breakdown. My question is: 👉 Is there a way to export an Allocations trace in XML with Call Tree details using xctrace? 👉 If not, is there an API or recommended workflow to automate this instead of exporting manually from Instruments GUI? Thanks in advance for your help!
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0
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0
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365
Activity
Sep ’25
Custom instrument interval color from aggregate
I'm working on a custom instrument that displays intervals from os_signpost data. I'd like to color the intervals in the graph based on data from an accompanying aggregate. For example, color the interval red if its duration is greater than 3 standard deviations from the mean. Is this possible?
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0
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0
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323
Activity
Nov ’25
Battery Consumption Analysis Using Xcode Instruments
I have been working on battery consumption analysis for my application, and as part of this effort, I wanted to understand how competitor apps behave under similar usage conditions. To do this, I downloaded competitor apps from the App Store and attached them to Instruments via Xcode. I then executed a defined set of manual test scenarios to simulate real user behavior. During these tests, the iPhone was connected to a Mac and charging continuously, which meant that System Power Usage logs were not generated in Instruments. However, I was able to capture detailed metrics such as: Network usage CPU load GPU activity Display and brightness impact Other runtime performance characteristics Since direct battery drain data was unavailable, I used derived analysis (with AI assistance) to estimate approximate power consumption based on the above metrics, assuming real-device (battery-powered) conditions. According to Apple documentation, System Power Usage in Instruments is not directly tied to the device’s battery percentage. Instead, it appears to be computed using contributing factors such as CPU, network, display, and other subsystem activity. This raises a few important questions about data reliability and methodology. Key questions: How reliable are Instruments-based metrics (CPU, network, display, GPU) for estimating real-world battery consumption when the device is charging? Can these metrics be safely used as a comparative baseline between competitor applications, even if absolute battery drain values are unavailable? Is the System Power Usage instrument essentially a derived model based on subsystem activity, and if so, does it remain accurate when the device is not discharging? From Apple’s perspective, is this a valid approach for relative power comparison, provided that: The same device is used OS version is identical Test scenarios are consistent and repeatable Based on these findings, would it be reasonable to proceed with instrumenting our own application, run the same scenarios, and draw conclusions using relative comparisons rather than absolute battery percentages? The intent is not to claim exact battery drain numbers, but to establish a directionally correct and repeatable comparison that can guide performance optimizations in our own application. I would like to understand whether this methodology aligns with Apple’s recommended practices, or if there are limitations or inaccuracies I should be aware of before relying on these results for decision-making.
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0
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531
Activity
Jan ’26
iPhone 16pro cpu counter: INST_ALL vs Instructions(FIXED_INSTRUCTIONS)
what is the diff between INST_ALL and Instructions(FIXED_INSTRUCTIONS)? also CORE_ACTIVE_CYCLE VS Cycles(FIXED_CYCLES)
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0
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214
Activity
Jan ’26
The best way to build, test and upload an iOS app without owning a Mac
Hi everyone, I’m developing a cross-platform mobile app (React Native) but I don’t currently own a Mac. What is the most reliable and professional way to: Build the iOS version Test it properly (real device / TestFlight) Upload it to the App Store Are cloud Mac services (like MacinCloud, AWS Mac, etc.) considered stable for production release workflows? Is there any fully supported workflow without direct access to a physical Mac? Would appreciate real-world experience from developers who faced the same situation. Thanks in advance.
Replies
0
Boosts
0
Views
244
Activity
Feb ’26
Is dtrace & dtruss supported on current macOS?
When I try to run dtruss on a command line program (freshclam) I see: $ sudo dtruss -a /usr/local/bin/freshclam 2>&1 | tee ~/tmp/dtruss.out dtrace: system integrity protection is on, some features will not be available dtrace: failed to execute /usr/local/bin/freshclam: DTrace cannot instrument translated processes I did some research and found advice on how to enable dtrace use via running: csrutil enable --without dtrace in a terminal running in macOS recovery mode. When I do that I see a warning saying this is an unsupported configuration and that it will allow unsigned kernel modules to be loaded. This is not what I want, I just want to run dtruss on a program while keeping all the other SIP protections in place. Why can't I just use sudo to grant the privileges for dtrace to work? All of this has me wondering if Apple intends for developers to use dtruss/dtrace in the current macOS?
Replies
0
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0
Views
179
Activity
Feb ’26
How to programmatically determine fixed CPU frequency for memory latency benchmarking on Apple Silicon?
Hi everyone, I am developing a benchmarking tool to measure memory latency (L1/L2/DRAM) on Apple Silicon. I am currently using Xcode Instruments (CPU Counters) to validate my results. In my latest run for a 128 MB buffer with random access, Instruments shows: Latency (cycles): ~259 cycles (derived from LDST_UNIT_OLD_L1D_CACHE_MISS / L1D_CACHE_MISS_LD). Manual Timer Result: ~80 ns. To correlate these two values, I need the exact CPU Frequency (GHz) at the time of the sample. My Questions: Is there a recommended way to programmatically fetch the current frequency of the Performance cores (p-cores) during a benchmark run? Does Apple provide a "nominal" frequency value for M-series chips that we should use for cycle-to-nanosecond conversions? In Instruments, is there a hidden counter or "Average Frequency" metric that I can enable to avoid manual math? Hardware/Software Environment: Tool: Instruments 26.3+ (CPU Counters Template). Chip: A19, iPhone 17 pro. OS: 26.3.
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0
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0
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541
Activity
Mar ’26
Question about UX/UI in a Connect mobile app
Is it possible to change the order of Cards in a Trends/Units screen like that (in a such order): Free In-App Paid Free iOS/watchOS/tvOS Free macOS In-App iOS/tvOS In-App macOS Paid iOS/watchOS/tvOS Paid macOS
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0
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0
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161
Activity
Mar ’26
Subject: [SDK / Instruments] Clarification on Runnable & Blocked Time Semantics — Customers Misinterpreting as CPU Usage
Subject: [SDK / Instruments] Clarification on Runnable & Blocked Time Semantics — Customers Misinterpreting as CPU Usage Hi Apple Developer Technical Support Team, I hope this message finds you well. I am writing to seek urgent clarification on a profiling question that is directly impacting our SDK customers. Context We provide an iOS SDK that is integrated into third-party applications. Our SDK includes a background monitoring thread created via: -[NSObject performSelectorInBackground:withObject:] As documented, threads created through this API carry a default (relatively low) scheduling priority. Inside the thread, we call sleep(1) once per second for periodic idle intervals, and we collect CPU usage metrics using kernel APIs: • task_threads() • thread_info() Both calls involve kernel-level operations and are known to trigger context switches internally. The Core Issue — Customer Misinterpretation When our customers profile their apps using Instruments with "Context Switch Sampling" enabled, they observe that our SDK thread shows a large proportion of time labeled as "Runnable" and "Blocked". A representative example: • Total (wall clock): 4.30 s — 100% • Runnable: 3.06 s — 71.4% ← customers flag this as high CPU usage • Blocked: 1.05 s — 24.5% • Running: 176 ms — 4.1% ⚠️ Our customers are interpreting the "Runnable" time (71.4%) as CPU consumption by our SDK, and are raising concerns that our SDK is degrading their app's performance. We strongly believe this interpretation is incorrect — a thread in the "Runnable" state is merely waiting in the scheduler's ready queue and has NOT been assigned to any CPU core, therefore it should NOT consume any CPU resources. However, we need an official confirmation from Apple to address our customers' concerns definitively. Our Questions Do the time values shown next to "Runnable" and "Blocked" in the Time Profiler call tree represent wall-clock waiting time (i.e., time spent in that state), or actual CPU consumption time? Does a thread in the "Runnable" state consume any CPU resources on the device? We want to confirm clearly: does Runnable time contribute to CPU load or battery drain in any way? Is it correct that the high Runnable time observed is caused by the combination of: a. The low thread scheduling priority assigned by performSelectorInBackground:withObject:, and b. Context switch overhead introduced by the task_threads() and thread_info() kernel calls? Is there any official Apple documentation that explicitly describes the semantics of "Runnable" and "Blocked" time in Instruments, which we could reference when communicating with our customers? An authoritative answer from Apple would allow us to accurately explain the profiling data to our customers and clarify that the high "Runnable" time does NOT represent CPU consumption by our SDK. Thank you very much for your time and support. Best regards
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Apr ’26
[SDK / Instruments] Clarification on Runnable & Blocked Time Semantics — Customers Misinterpreting as CPU Usage
Hi Apple Developer Technical Support Team, I hope this message finds you well. I am writing to seek urgent clarification on a profiling question that is directly impacting our SDK customers. Context We provide an iOS SDK that is integrated into third-party applications. Our SDK includes a background monitoring thread created via: -[NSObject performSelectorInBackground:withObject:] As documented, threads created through this API carry a default (relatively low) scheduling priority. Inside the thread, we call sleep(1) once per second for periodic idle intervals, and we collect CPU usage metrics using kernel APIs: • task_threads() • thread_info() Both calls involve kernel-level operations and are known to trigger context switches internally. The Core Issue — Customer Misinterpretation When our customers profile their apps using Instruments with "Context Switch Sampling" enabled, they observe that our SDK thread shows a large proportion of time labeled as "Runnable" and "Blocked". A representative example: • Total (wall clock): 4.30 s — 100% • Runnable: 3.06 s — 71.4% ← customers flag this as high CPU usage • Blocked: 1.05 s — 24.5% • Running: 176 ms — 4.1% ⚠️ Our customers are interpreting the "Runnable" time (71.4%) as CPU consumption by our SDK, and are raising concerns that our SDK is degrading their app's performance. We strongly believe this interpretation is incorrect — a thread in the "Runnable" state is merely waiting in the scheduler's ready queue and has NOT been assigned to any CPU core, therefore it should NOT consume any CPU resources. However, we need an official confirmation from Apple to address our customers' concerns definitively. Our Questions Do the time values shown next to "Runnable" and "Blocked" in the Time Profiler call tree represent wall-clock waiting time (i.e., time spent in that state), or actual CPU consumption time? Does a thread in the "Runnable" state consume any CPU resources on the device? We want to confirm clearly: does Runnable time contribute to CPU load or battery drain in any way? Is it correct that the high Runnable time observed is caused by the combination of: a. The low thread scheduling priority assigned by performSelectorInBackground:withObject:, and b. Context switch overhead introduced by the task_threads() and thread_info() kernel calls? Is there any official Apple documentation that explicitly describes the semantics of "Runnable" and "Blocked" time in Instruments, which we could reference when communicating with our customers? An authoritative answer from Apple would allow us to accurately explain the profiling data to our customers and clarify that the high "Runnable" time does NOT represent CPU consumption by our SDK. Thank you very much for your time and support. Best regards
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Apr ’26
[SDK / Instruments] Clarification on Runnable & Blocked Time Semantics — Customers Misinterpreting as CPU Usage
Hi Apple Developer Technical Support Team, I hope this message finds you well. I am writing to seek urgent clarification on a profiling question that is directly impacting our SDK customers. Context We provide an iOS SDK that is integrated into third-party applications. Our SDK includes a background monitoring thread created via: -[NSObject performSelectorInBackground:withObject:] As documented, threads created through this API carry a default (relatively low) scheduling priority. Inside the thread, we call sleep(1) once per second for periodic idle intervals, and we collect CPU usage metrics using kernel APIs: • task_threads() • thread_info() Both calls involve kernel-level operations and are known to trigger context switches internally. The Core Issue — Customer Misinterpretation When our customers profile their apps using Instruments with "Context Switch Sampling" enabled, they observe that our SDK thread shows a large proportion of time labeled as "Runnable" and "Blocked". A representative example: • Total (wall clock): 4.30 s — 100% • Runnable: 3.06 s — 71.4% ← customers flag this as high CPU usage • Blocked: 1.05 s — 24.5% • Running: 176 ms — 4.1% ⚠️ Our customers are interpreting the "Runnable" time (71.4%) as CPU consumption by our SDK, and are raising concerns that our SDK is degrading their app's performance. We strongly believe this interpretation is incorrect — a thread in the "Runnable" state is merely waiting in the scheduler's ready queue and has NOT been assigned to any CPU core, therefore it should NOT consume any CPU resources. However, we need an official confirmation from Apple to address our customers' concerns definitively. Our Questions Do the time values shown next to "Runnable" and "Blocked" in the Time Profiler call tree represent wall-clock waiting time (i.e., time spent in that state), or actual CPU consumption time? Does a thread in the "Runnable" state consume any CPU resources on the device? We want to confirm clearly: does Runnable time contribute to CPU load or battery drain in any way? Is it correct that the high Runnable time observed is caused by the combination of: a. The low thread scheduling priority assigned by performSelectorInBackground:withObject:, and b. Context switch overhead introduced by the task_threads() and thread_info() kernel calls? Is there any official Apple documentation that explicitly describes the semantics of "Runnable" and "Blocked" time in Instruments, which we could reference when communicating with our customers? An authoritative answer from Apple would allow us to accurately explain the profiling data to our customers and clarify that the high "Runnable" time does NOT represent CPU consumption by our SDK. Thank you very much for your time and support. Best regards
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Apr ’26
APU H series
What about a studio rendering audio interface with airpods max, when linked has a usb-c*thunderbolt's cable. Them can bring Use and Space at utility. +can bring 32 bits dept into sound edit +can bring Audio Spatialisation +and a bunch of codecs to encode ogg capabilties or atmos/dtsX fidelity -since the latency became minimalist at bluetooth 6.0, a think could look forward about cableless capability upforth.
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3w
(iOS 26) - PowerProfiler trace file cannot be opened
I kept CoreLocation’s startUpdatingLocation running for a full day and used Performance trace - PowerProfiler to track the power usage during that time. The trace file was successfully generated on the iOS device, and I later transferred it to my MacBook. However, when I tried to open the .atrc file, I received the following warning: The document cannot be imported because of an error: File ‘/Users/jun/Downloads/PowerProfiler_25-06-16_181049_to_25-06-17_091037_001.atrc’ doesn’t contain any events. Why is this happening? Is there a known issue with PowerProfiler in iOS 26, or am I missing something in the tracing setup? Note: The .aar file and the extracted .atrc file are not attached here, as forum uploads do not support these formats.
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Jun ’25
Bottleneck analysis is not available in my Instruments
Hello, I wanted to try new Bottleneck analysis mode showcased in recent Apple's video, however when I select CPU Counters template in Instruments, there's no such option - just the same old "sample by Time/Events". I have the latest XCode 16.4 and OS Sonoma 15.5, the system is M4 Max. While Instruments shows version 16.0 in About dialog for some reason (a bug?), it definitely comes from the Xcode 16.4 package and the build id is the same (16F6) as for XCode 16.4. I also checked just in case on another M1 system (all updated as well) and it's all the same. Any clues why Bottleneck analysis is missing? Regards, Maxim
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Jul ’25
Question about Metrics Analysis in Xcode 26
Hello, I have recently been using the new Power Profiler tool introduced in Xcode 26 to analyze the power consumption of my app. My app primarily operates in the background. During a profiling session of 5 hours and 30 minutes, I observed that the app was active in the background for 2 hours and 30 minutes, while it remained in a suspended state for the remaining 3 hours. While the Power Profiler allows me to identify spikes in CPU, networking, and other resource usage at specific points, it is difficult to determine whether these values are objectively considered high. For example, in my case, the total QoS Execution Time of CPU Impact recorded during the 5 hours and 30 minutes was 12.18 seconds. I am wondering whether this is considered a good metric. Could you please advise on the following points? 1. Is there a commonly accepted or recommended ratio between app active time and CPU time that developers should aim for? 2. Are there any guidelines or reference materials on how to interpret CPU usage and other resource metrics for apps that primarily run in the background? Any insights or advice would be greatly appreciated. Thank you.
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316
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Aug ’25
Complete control flow trace... possible?
Is there an xctrace instrument capable of capturing the complete control flow of a process? So far the best I can find is high-frequency sampling, but what I need is a trace of all machine instructions executed. This is easily done on Linux/Intel using the perf tool, which provides access to Intel's hardware-assisted tracing module (ptrace). According to the arm specification, my mac mini M1 (armv8.4-a) and M4 (armv9.2-a) both have hardware support in the CoreSight ETM (embedded trace macrocell) for full instruction tracing (i.e., no sampling, no gaps, no statistics--capturing the complete execution path). But it's not clear how I can access these features, if they are supported by the macos XNU kernel at all. After hours of searching online, it's nothing but dead ends. Any suggestions for documentation or Xcode tools or open-source tools or built-in macos tools would be much appreciated!
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Aug ’25