RAM installation question

[drewaz]

late 2015 iMac

the stock 4GB RAM sticks are in slots 1 and 3
I am adding 2 8GB sticks ... should I place them in the two open slots? or should the 4GB stick be in the same bank .... and the 8GB sticks be in the same bank?

Sorry if this has been answered already

 

[zhaoxin]

You should put 8Gx2 in the current empty slots.

 

[Boost3devo]

I installed apple stock 4gb ram on 1&2, and 8gb sticks on 3&4. Could be wrong but at the moment no error or problem, imac detects the 24gb @1867.

 

[drewaz]

thanks. I guess it doesn't matter!

 

[twilexia]

I installed apple stock 4gb ram on 1&2, and 8gb sticks on 3&4. Could be wrong but at the moment no error or problem, imac detects the 24gb @1867.

That's interesting. When I installed two 8 GB 2133mhz along with the 2 4gb Apple stock ram, it recognized the entire thing at 1600 mhz.

 

[drewaz]

That's interesting. When I installed two 8 GB 2133mhz along with the 2 4gb Apple stock ram, it recognized the entire thing at 1600 mhz.

how do you find out if it's 1600 or 1867?

 

[DamnDJ]

how do you find out if it's 1600 or 1867?

Apple Menu > About this Mac > System Report > Memory

 

[drewaz]

Apple Menu > About this Mac > System Report > Memory

got it. I think I'll put the 8GB sticks in the empty slots and see how it goes.

 

[zhaoxin]

please see this.

 

[drewaz]

please see this.

thanks ... if I understand it, I can just add my 8gb sticks to the empty slots?

 

[zhaoxin]

thanks ... if I understand it, I can just add my 8gb sticks to the empty slots?

Yes. Without dual channel, your memory can still be used fully as the other one did above. But your memory's bandwidth is half of the dual channel's. So you computer will run a little slower than it should be, but still works.

If you know raid, you can think dual channel as the raid0 of the two rams.

 

[drewaz]

Placed the Crucial RAM in the 2 open slots
working perfectly
24GB at 1867