CL4-4-4-8 DDR2-533 RAM or CL5-5-5-15 DDR2-667 RAM For MacBook

littlechu

Hi everyone,



I was researching which ram to use for my MacBook (1.83) and was wondering is there any huge performance different on using the DDR2-533 vs DDR2-667. In general I am planning to upgrade it from 512 MB to 2GB. The DDR2-533 is 2/3 the price of the DDR2-667 but if there is a big performance issue, I can buy them one stick at a time.

canadiandude

I was under the impression that the RAM had to be DDR2-667...but I suppose it could take slower RAM. I upgraded my RAM with 2 GB of DDR2-667 PC 5400 CL5 g.skill RAM and it has worked like a charm. The CL value is not as important with DDR2 RAM as it was with DDR RAM. I would however go with the DDR2-667 modules.

mr. h

You have no choice: DDR2-533 RAM will not work (or, it may work but will be very unstable). You can use faster RAM on slower busses (e.g. 667 RAM on a 533 bus), but not the other way around. The MacBook system bus is DDR2-667, so you must use at least DDR2-667 RAM.

jeffdm

Quote:

Originally Posted by Mr. H


You have no choice: DDR2-533 RAM will not work (or, it may work but will be very unstable). You can use faster RAM on slower busses (e.g. 667 RAM on a 533 bus), but not the other way around. The MacBook system bus is DDR2-667, so you must use at least DDR2-667 RAM.

It looks like other Core Duo notebooks are available with 533 memory, so I think the chipset should be able to use it stably. The memory has a chip on it that identifies the speed and such, so I don't think it will try to run above the slowest identified speed in the system.



However, I don't think the cost savings is worth it the speed reduction. So you save what, $20 a stick? For a $1100 notebook, it's not worth slowing it down, IMO.

lundy

Apple has the memory controller clocked at 667 DDR, so even though the Core 2 Duo can work with 533, in the case of the MBP it won't.