21.5" iMac - Mid 2010 upgrade

[indisen]

21.5" iMac - Mid 2010 , need to upgrade the RAM and to SSD, Can some one help with this to know what is the Maximum can do with optimal speeds.

 

[iTurbo]

I've upgraded one to 16 GB RAM (max) and a 1 TB SSD replacing the stock hard drive and loaded it with MacOS Sierra. Check ifixit.com

The RAM is a piece of cake; the SSD a bit harder but not bad.

 

[Willo34]

The Max possible for your machine is a 2TB HD.