Do all RAM memory slots have to be the same sized module? For four slots can you use two 2GB and two 4GB modules?

stuartfromhudson wrote:

Do all RAM memory slots for an iMac desktop have to be the same sized module? For four slots can you use two 2GB and two 4GB modules, assuming the same speed and type 1333MHz DDR3 ?

Thanks

Yes you can, you will pay for it in marginally slower performance than if a set of matching chips had been installed, but, it's marginal.

No, they do not all have to be the same although many here have found that the should be the same in side-by-side slots. I am currently running the configuration below. Many on this forum, as do I, also recommend that you use only Crucial or OWC RAM chips as bargain brand RAM often will not work.

Yes you can install different size pairs in a Mac with 4 slots.

However, Mac are picky and it is best to purchase modules from suppliers like OWC or Crucial that specialize in Mac memory.