Technical Q&A QA1130

PC100 SDRAM DIMMs on the Flat Panel iMac

Q: The Flat Panel iMac Developer note states that "both (RAM) expansion modules for the iMac are 3.3 volt, unbuffered, 8-byte, non-parity, and PC133 compliant." However, Table 2-1, Buses supported by the Pangea IC, clearly states that the Memory bus is 64 bit at 100MHz. Can PC100 SDRAM be used in the Flat Panel iMac?

A: The Pangea memory controller has very tight timing margins for the Flat Panel iMac. The PC133 SDRAM modules provide a better guarantee of meeting these margins than the average PC 100 modules. Coupled with the industry's move to PC133, it was decided to specify the PC133 SDRAM modules for this product.

It is possible that fast PC100 module could be designed and used in the Flat Panel iMac, but both the designer of such modules, as well as the user, should do significant testing on the Flat Panel iMac before claiming compatibility.

[Mar 19 2002]