24GB RAM? Late 2012 27" iMac

[Felder71]

This is the correct RAM placement.

The new RAM must be inserted where the original Apple RAM was located.

The processor goes to those slots first, so it will see and use the new 16GB first and not use the old 8GB unless needed for more than 16.

Can someone explain this? What exactly happens if you don't do it this way? My system says it has 24 GBs of RAM and it just slowly gobbled up whatever was there as it was needed. I didn't see where it "stopped" at some point to start using the extra 16 GB chips. It's just using what is there. I mean, if it needs RAM, it should take what it finds. It really shouldn't matter which chips it utilizes first, if they are the same CLL, speed, etc. Or maybe I have no idea what I'm talking about...

 

[Hallowedclover]

I bought 16GB Crucial RAM. I'm going to follow what the guy in this below article did when i get my iMac.

http://www.macworld.com.au/help/how-to-install-extra-ram-memory-in-the-new-imac-84952/

 

[lixuelai]

8/8/4/4 in About This Mac is the same as 8/4/8/4 physically on the machine. For some reason Apple just decided to reorder how the slots are displayed in OSX.

 

[robjulo]

Can someone explain this? What exactly happens if you don't do it this way? My system says it has 24 GBs of RAM and it just slowly gobbled up whatever was there as it was needed. I didn't see where it "stopped" at some point to start using the extra 16 GB chips. It's just using what is there. I mean, if it needs RAM, it should take what it finds. It really shouldn't matter which chips it utilizes first, if they are the same CLL, speed, etc. Or maybe I have no idea what I'm talking about...

There is another fairly lengthy thread somewhere that gives an explanation. In that thread, it was said that both Apple and Crucial recommended putting the 8 gig sticks where the original 4 were and then putting the 4 in the previously unused slots.

I'll try and dig the thread up later when I get home.

 

[robjulo]

There is another fairly lengthy thread somewhere that gives an explanation. In that thread, it was said that both Apple and Crucial recommended putting the 8 gig sticks where the original 4 were and then putting the 4 in the previously unused slots.

I'll try and dig the thread up later when I get home.

Here is the thread I was thinking of

https://forums.macrumors.com/threads/1499124/

 

[andydajo]

I assume this is the correct RAM?

http://www.crucial.com/uk/store/mpartspecs.aspx?mtbpoid=CFFEC046A5CA7304

Yep, that's the stuff.

 

[virginblue4]

Have now ordered the RAM. Thanks for all the replies and tips

 

[artwindows]

I just got the 27" iMac 3.2ghz
I have 8g ram.
My brand new system seems slow after loading on my transfer of 565g to the new 1T drive. Does upgrading ram to 24g per this discussion make a big difference? It's depressing that I just got this and still getting the beach ball spinning.

Thx. I'm sure SSD is the answer but maybe when prices come down a bit more. That was the plan. But would love to know if this will do the trick for now. I do run cs4 photoshop along with other open apps.