27-inch iMac upgrading RAM

[Mountain Turtle]

i just bought a new 27-inch iMac. It comes stock with 2x2GB RAM in the upper slots. There are two empty lower slots. I want to put in 2x4GB RAM in the lower slots. Does it matter if the RAM is different between the upper and lower?? Is it going to affect the computer's performance?? I was under the impression that the upper/lower slots only needs to be paired with respect to each other.

Thanks guys

 

[Fuchal]

Yes that will work fine.

 

[HobeSoundDarryl]

In the same situation yesterday, OWC told me that it didn't matter if the new ram was in either set of slots (so Apple ram could stay where it is and OWC ram could go into the 2 empty slots). They said there would be no performance difference. And they said it was fine to install 8GB of ram in the 2 open slots to go with the 4GB ram supplied by Apple as stock (for a total of 12GB ram).

The only thing that mattered was being sure that like ram was paired appropriately, meaning you shouldn't pull the Apple ram out of one of the 2 slots it will come in, move it to one of the other slots, then throw the new ram into the 2 open slots that would remain (pairing a 2GB stick with a 4GB stick, etc).

So, my plan is to stick the 8GB ram in the 2 open slots, and leave the Apple stock 4GB ram in the slots in which they placed it.