Memory cards usage

[timearthur]

Sounds like something that'd have information posted on Apple or elsewhere, but I can't find it. I have a 2014 27" iMac with four available memory card slots. Two are filled with 4GB cards. My Fusion drive crashed so I'm running only a magnetic drive and would like to boost my RAM. In days of old, memory sims had to be added in pairs, and those in the pair had to be of the same RAM size. Are there any limitations on what I can configure with my two open slots? That is, could I install just one more 8GB card? Apart from that issue with fusion this machine works like a champ. Thanks!!!

 

[MacInWin]

Welcome to the forum.

You can mix memory size in the slots, although there is a very slight performance hit if you do that. However, the statement,

My Fusion drive crashed so I'm running only a magnetic drive and would like to boost my RAM.

is confusing. Adding RAM will not help with the speed degradation you have from losing the Fusion drive and going back to a spinner. Going from 8GB to 12GB of RAM will result only in a very small performance improvement, possibly none at all. I would recommend you look at Activity Monitor and the Memory tab to see if there is any problem before I invested in any memory upgrade. If the memory pressure is green, and if Swap Used is low, I wouldn't bother with a memory upgrade but rather spend the money on a replacement SSD drive for the system.

 

[timearthur]

I didn’t add those details as I didn’t think they were material. First, thanks for letting me know I can mix sizes in the slots. Second, activity monitor has been ok for relatively low activity usage but I use FCP and don’t want to be hampered with speed when doing that. Still, 8gb so far has been fine. I like your advice to wait to see if the stats compel me to add more later. As for the ssd I went from a 3tb fusion so cannot llive with less than 1tb ssd and the price point is prohibitive. The 4tb 5400 works decent enough. The fusion has 128gb flash on it, too bad I cannot get to that pet alone— or can I?

Thanks again.

 

[chscag]

Well, if you can do the work yourself, a replacement SSD in lieu of another troublesome fusion drive might be well worth it. Granted, opening up a glued together iMac is not exactly an easy job but it can be done. Take a look at the instructions at www.ifixit.com and see if you're up to it. You can buy a large SSD for much less cost than having Apple do the work for you.

 

[MacInWin]

Another option is a smaller boot SSD of your 1Tb range, and then put the files for FCP on an external drive. Both USB3 and Thunderbolt are really quick interfaces so loading times would be pretty good.