Santa Rosa stödjer inte 800 MHz-minnen. Jag googlade åt dig och hittade detta:
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. Memory can be expanded to 4 GB (about $250 on the aftermarket, or a $750 option from Apple).
Se även det här:
Couple thing to understand here...
First, DDR2-800 is not running at 800mhz. The bus speed is half that, 400mhz.
Now, let me give you an overview of the FSB, and the relation between that and your ram speed.
These new chips are kinda like the e4x00 desktop series. In actuality, the FSB is 200mhz [not 800mhz], but 'quad-pumped'. Thus, 4x200=800, and you have an 800mhz FSB.
Now, the ram does NOT necessarily run 1:1 with your FSB speed. Instead your ram speed is determined by a ratio. Your ram speed is the product of both the FSB and that ratio.
So, for example in stana rosa systems...
Running on a 1:1 ratio with the 800mhz FSB C2D should result in a ram speed of DDR2-400. Now, clearly that would offer lousy memory bandwidth, so a different ratio is being used. I suspect in this case a 2:3 ratio is used, resulting in DDR2-600. Now, in a perfect world you could add DDR2-800 modules and it should kick the ratio up to 1:2. Its hard to say if that will actually work though.
From my own personal experience with P965 based desktop systems, you kinda see diminishign returns passed a certain point. The optimal configuration is to push the FSB as high as possible and keep the ram 1:1. In laptops this isn't possible, or practical. Anyway, back to the main point.
