Chosen Solution
I’m planning to upgrade my recently restored iMac and would like to know if I could use 800 MHz sticks or if I’m stuck with 667. Also, I’ve heard that this machine can go beyond its 4gb limit to 6gb. Is this true?
You won’t get any better performance as the systems I/O is clocked based. The CAS and RAS timing can be too short causing errors when using too fast RAM. And yes while Apple only lists 4 MB you can go upto 6 MB using one 2 GB SO-DIMM and one 4 GB SO-DIMM and the speeds need to match! I would stick to the spec’ed RAM.
