xcode 9 (9A235) horrible performance...

Absolutely pathetic. I was excited at WWDC '17 to see speed improvement as a top priority. I updated to the App Store version and now I can't even function. Absolutely terrible. Bugs in the code editor, beach-balling left and right. Runs my CPU at 100-150% CONSTANTLY. This needs to be addressed IMMEDIATELY!

It may relieve your mind to complain here, but it has no practical effect. If Xcode isn't working to your satisfaction (which include usability and performance as well as functionality), submit a bug report. That's how things change.

Also, note that an Xcode 9.1 beta was posted today. It already contains fixes for some of the things that have been flagged in these forums, and it may have changes that help your problem. Obviously, reporting bugs during beta is likely a faster path to change than after a final release, so get going with that now.

I've been having the same issues. SourceKit takes up more than 100% of the CPU at times, and it rebuilds everytime I type anything. the autocomplete has been horrendous, to say the least.

Same issue here, storyboard i think is slower than ever, i have to force quit at least a couple of times every day, and everything is just to slow. Im on a brand new mac book pro with 16 gigs.

Just issued a bug report. Hope they get it fixed ASAP.

Xcode 9 Storyboards are a Disaster! We have some large ones with 50-80 GUI's, so it has always taken a few seconds to load, however with Xcode 9 they are taking 5 minutes and longer. When switching back to text editor, same delay.

We have tested a storyboard with a handful of GUI's, not as bad but our apps use 4 storyboard that each have 50 or more GUI's so breaking them up is not an option. The real solution is to probably not use storyboards, but that would involve major time.

We have a new update we're trying to finish and are debating simply returning to Xcode 8 so we can get our work done.

Can't waste any more time on the "Forum" which seems totally useless. Probably a bunch of interns that read this and laugh!

Maybe it's like the iPhone 8...better to wait for 10? Opps X

( here's a hint as to how seriously Apple takes the "Forum" the spell checker doesn't recognize storyboard! , or Xcode or iPhone NICE!)

Same experience here; 8 was much better in terms of performance. With 9, restarting XCode every hour became part of the development process.

Here are couple serious issues:

1) The SourceKitService goes haywire with the CPU (>100%) every hour and I have to delete the /DerivedData/ModuleCache folder and restart xcode to get it back to normal for another hour.

2) Sometimes opening a storyboard causes the "Interface Builder Cocoa Touch Tool" to go 200% CPU.

3) Every 3rd or 4th run the app does not run on external iPhone and I have to clean the project.

I am using the New Build System and my project takes 10 minutes to compile. My work is a disaster because I lost a lot of time compiling. Xcode 9 is the worst Xcode ever.

Xcode 8 StoryBoard performance was pathetic, but Xcode 9 is unusable. Same exact symptoms. The only route I can see is chunking the storyboard into multiple storyboards...a ton of unproductive work.

Same here...thinking of chunking my storyboard into multiple smaller storyboards...sigh

Remember when SourceKit would constantly use 100% of CPU in the background and kill your battery life with XCode 8? Oh, yea, that's what it does with XCode 9 as well.

I'm typing now, and I have to wait every few few chars for the "lightning fast" editor to catch up. Autocomplete is taking auto-forever.

Mine were even worst than yours my Xcode 9 stop responding when editing the storyboard 😠. Should we waiting for Xcode 10?!?

Same here. Jumping to definition takes 5 seconds, simulator shows up noise, etc. My perception is that Xcode is in beta forever 😟

If you mean a perpetual beta, I agree - not uncommon in the industry these days, apparently.

Same here. Storyboard with 3 viewcontrollers = virtually unusable. MBP 15-inch, 2017, 3.1 GHz i7, 16 GB RAM, 1 TB SSD. At least Apple can't say my machine is too old, lol.