2011 iMac RAM Upgrade: 24GB Possible?

[gmanist1000]

I currently have 12GB of RAM installed on my 2011 iMac. Apple says it only supports 16GB of RAM, but in reality it supports 32GB.

My question is, will it support 24GB? I want 2x8GB and 2x4GB. Will this work? Or does it have to be 32GB with 2x8 and 2x8?

 

[justperry]

2 X 4 + 2 X 8 should work but keep in mind that the speed of the RAM will be set to the lowest RAM speed, so if the new ones are 1600 MHz but the old RAM is 1333 MHz it will be set at 1333 MHz.

 

[ConsiderPhlebas]

About 2 weeks ago I added two 8 GB Crucial cards to my mid 2011 27" iMac that brought the memory up from 8 GB to 24 GB. Had no problems at all.

 

[harlex]

How did your iMac work with the extra ram and did you n0tice any difference?

 

[ConsiderPhlebas]

How did your iMac work with the extra ram and did you n0tice any difference?

I got a little back from the performance hit when I updated from SL to ML but not a lot. A slight difference when I am doing some video or photo work.

The main reason I increased the memory was a good deal I found on Amazon and since I plan on keeping my iMac for awhile I beefed it up for possible future needs.

 

[gmanist1000]

About 2 weeks ago I added two 8 GB Crucial cards to my mid 2011 27" iMac that brought the memory up from 8 GB to 24 GB. Had no problems at all.

I've been hearing mixed things about how to go about installing the RAM into the slots.

I have heard that it's best to install 2x4 into one slot and 2x8 into the other. I have also heard it's best to install 4GB and 8GB into one slot, and 4GB and 8GB in the other slot to get 12GB in each slot.

The reason I ask is for the dual channel configuration.... can anyone shed some light onto this for me? What's the best way to install them so there is no performance hit? Thanks.

 

[ConsiderPhlebas]

I

I have heard that it's best to install 2x4 into one slot and 2x8 into the other. I have also heard it's best to install 4GB and 8GB into one slot, and 4GB and 8GB in the other slot to get 12GB in each slot.

No hardware expert but I think you should have the same size memory card in each slot to have dual channel capability.

I already had the two 4 GB in slot(s) 0 and installed the two 8 GB in the empty slot(s) 1

 

[gmanist1000]

No hardware expert but I think you should have the same size memory card in each slot to have dual channel capability.

I already had the two 4 GB in slot(s) 0 and installed the two 8 GB in the empty slot(s) 1

Ok, thanks for the advise.