Confused with RAM..

pretty much the same

you can fit most laptop DDR2 667 RAMs into the white MacBook and they're very cheap to buy now

 

If you don't happen to have some around
http://eshop.macsales.com/item/Other World Computing/53IM2DDR4GBK/
4GB for $45 bucks, might find some cheaper though.

 

That RAM has a 667 MHz front-side bus speed. It's slower than the 800 MHz bus speed found in the new white MacBooks.

RAM that has 200 pins, SODIMM, PC5300 RAM with a speed of 800 MHz (or faster) will work with the new white MacBooks. Perhaps 667 MHz RAM (like the link provided earlier) will work, but why the heck would you bother?

Basically, any RAM with a bus speed of 800 MHz (e.g: 800 MHz, 1066 MHz) will work on your system, which should have a bus speed of 800 MHz (I think). If you buy 1066 MHz RAM for your white MacBook, it'll just scale down the speed and operate at your computer's bus speed (800 MHz). RAM that is slower than your system's bus speed (e.g. 667 MHz RAM on your system, which has an 800 MHz bus speed) slows your system.

 

All of the MBs besides the Aluminums use 667MHz. Otherwise, why would Apple sell the MB with 667MHz RAM? I know the FSB is 800MHz but does that automatically allow the RAM to run at 800MHz? I'm pretty sure it will run at 667MHz if it works. (It probably will work but it is a waste of money due to downclocking to 667.) The iMacs do use the 800MHz RAM though. You are going to want DDR2 PC2-5300 200-pin RAM 2X2GB. This Crucial set from Newegg is newly even cheaper than before with free shipping for $36.99 and no tax. That's a great deal.