Should I buy the imac with expandable memory slot for future os upgrade size?

Ya kinda need a crystal ball to answer that but in looking back at my situation I'd say yes, either buy an expandable machine or load it up with extra RAM direct from Apple when you purchase it. My mid-2010 21.5 inch i-Mac with 4 GB of RAM recently started slowing down after multiple OS updates since 2010. I was seeing a lot of spinning beachballs. I just added 8 GB of RAM and haven't seen the beach ball since. I am very happy I added the extra RAM.

I Always try to have a little more RAM on my computers that I think I'll need when I purchase them. Either have more ram installed when you order the iMac or purchase one with open slots for upgrading.

I Purchase my iMac 5K with only 8 GB RAM but it had two open slots. As soon as I received the iMac I purchased two 8 GB modules form Other World Computeing. That brought my RAM to 24 GB. I run multiple applications and the iMac runs smoothly.

You are welcome. I understand that Yosemite runs best with at least 8 MB, so the new OS updates outgrew my original RAM of 4 MB. No telling how much RAM future updates will require but I think I will be following the same logic as you when it is time for a new i-Mac. Good luck with your new computer.

pokey b wrote:

You are welcome. I understand that Yosemite runs best with at least 8 MB,

Surely you jest, the minimum is 2GB, and that runs pretty slow, at least 4GB and preferably more (as much as you can get) but it won't go with 8MB

Right you are, good catch. Sorry, "my bad". A typo, I meant to say "I understand Yosemite runs best with at least 8 GB of RAM".