Memory upgrade advice 2009 iMac

[Sam Luis Obispo]

A relative has an iMac with only 4 Gb of memory (have not taken it apart to verify, but my suspicion would be that there are two 2 Gb modules of memory). In order to upgrade the memory to 8 GB, could I insert a single 4 Gb module? or would I be better off inserting two 2 Gb modules?

 

[jerwin]

depends whether it is early 2009, or late 2009. The "early 2009" imacs had two slots; the "late 2009" imacs had four.

 

[Sam Luis Obispo]

depends whether it is early 2009, or late 2009. The "early 2009" imacs had two slots; the "late 2009" imacs had four.

Thanks, I believe it is the late 2009 iMac 10,1.

 

[redheeler]

It's generally better to have them in matched pairs (little bit better performance vs. 1x4 GB), so 2x2 GB is what I'd go with. You don't have to take the access door off to verify what's installed in it now, simply go to  > About This Mac and click the Memory tab.

 

[jerwin]

Thanks, I believe it is the late 2009 iMac 10,1.

apple's instructions are here.

https://support.apple.com/en-us/HT201191#2
[doublepost=1511593387][/doublepost]what OS is this imac using? High Sierra seems to like RAM.

 

[Sam Luis Obispo]

apple's instructions are here.

https://support.apple.com/en-us/HT201191#2
[doublepost=1511593387][/doublepost]what OS is this imac using? High Sierra seems to like RAM.

Currently runs Sierra. Occasional intermittent beachballs op up after you tell the computer to do something. I am assuming that this is the computer sending and retrieving information to hard drive (still original from 2009). Before upgrading the memory on my computer, saw the same thing. Going from 4 to 8 Gb made a noticeable improvement for me. Anyway, getting the matched memory and filling all 4 slots looks to run about $30 with OWC memory.