[fortepianissimo]

So someone told me that installing two modules of RAM of different sizes will slow down your PB. But someone else told me that's only true to PCs and PM G5.

Can anyone give some insight? Thanks!

[Luca Rescigno]

It won't matter with a PowerBook. Some PCs have the ability to use dual-channel RAM, where installing two RAM modules of the same size and speed in the correct slots will increase performance by a bit. The iMac G5 also works like this, if I remember correctly. The PowerMac G5 requires RAM to be installed in this fashion. Other than those two cases, though, there aren't any modern Macs that require any kind of memory matching.