iMac RAM

[rasmits]

I have a brand new 20" iMac. I knew not to buy RAM from Apple, so I tried looking on crucial to try maxing out to 4GB.

Crucial is recommending DDR2 677 (PC2 5300), but looking in the System Profiler I can see my iMac currently has DDR2 800 (PC2 6400). Obviously because they cost roughly the same, I'll get the 800mhz variety. A quick Google search and I found information that claimed the RAM in the iMacs will run at 677mhz anyway due to the Intel chipset they're using.

Can anyone give me a solid answer ? If I buy RAM at 800mhz, will it run at full speed or is it a waste of money (even if it's just a few dollars) ?

[bassplayinMacFiend]

I'd say if System Profiler recognizes the RAM as 800MHz then it is working at 800MHz. If the Mobo limited the RAM to 667MHz, then I would guess System Profiler would report the RAM as 667MHz.

Apple's spec sheet (http://support.apple.com/kb/SP485) lists the RAM as 800MHz so I'd go for that speed if you were looking to upgrade. Your iMac has a 1066MHz frontside buss so you'd definitely want to use as fast RAM as possible to keep that buss fed.