[SpecMode]

Just like the title says, I'm wondering if anyone has any idea or has read anywhere that PC2-6400 (DDR2-800) SO-DIMMs are compatible with the new Santa Rosa MacBook Pros. I've spotted a few available for purchase online, but before I put down the cash on one (seeing as they're still just a bit pricey) I'd like just a bit of reassurance that it won't make my new MBP asplode or anything.

And yes, I'm running multiple Google searches in parallel with this post.

[PB PM]

You need PC2-5300 DDR2 667Mhz chips, not the 6400s.

[Fahrenheit]

Where is Chucker?

[Mugge]

Well, as long as they are SO-DIMMs they will most likely still work despite being 800 MHz, but they will of course only run at 667 MHz.

Having said that, I didn't even know you could get SO-DIMMs at 800 MHz. It's not like there's much room for RAM heat-sinks in a notebook.

[SpecMode]

Well, I was curious, because the new MBP's Santa Rosa chipset has an 800MHz front-side bus - which means that technically, the PC2-5300 667MHz SDRAM is actually a bottleneck for the entire FSB.

My assumption is that Apple included PC2-5300 and stated that it was the only compatible type based on the limited availability of PC2-6400 SO-DIMMs. However, they are available, albeit somewhat pricey (but still cheaper than buying PC2-5300 direct from Apple): Crucial 2GB PC2-6400 SO-DIMM

EDIT: Well, finally found a good reason why I was mistaken.

Originally Posted by MacInTouch Santa Rosa MBP review There has been some confusion about the MacBook Pro's 667-MHz memory speed vs. the 800-MHz frontside bus. Although 800-MHz memory is available in the marketplace, Santa Rosa doesn't support it. 667-MHz memory, we are told, is effectively 33% faster than Santa Rosa can use, so the lack of 800-MHz memory should not handicap this computer.

Crucial 4GB kit it is, then.

[PB PM]

You could try it, but I wonder if it is not a memory controller issue. Only time will tell, let us know if it works.