Where can I buy the memory cards. After downloading El Capiton I have had nothing but problems. The photos are messed up. It runs slow. The beachball is there more than not.
iMac, early 2009
Do you mean RAM? It would help if you told us where you are located.
How much RAM do you currently have?
One place to start looking for RAM is OWC = mac-sales.com There are other vendors out there and Crucial is another recommended brand for RAM. OWC provides strong Mac support so if I have questions about what I am doing I often just go with them start to end in recognition of the support and it usually is worth the extra dollar or two.
I have a mid-2010 I-Mac that also originally had 4 GB or RAM. I did as Limnos suggested; added 8 more GB of RAM from OWC for approximately $100. The Mac runs well with latest version of El Capitan.
It may be something other than insufficient memory that's causing the problem. Download and run Etrecheck. Copy and paste the results into your reply. Etrecheck is a diagnostic tool that was developed by one of the most respected users here (and recommended by Apple Support personnel) in the ASC to provide a snapshot of the system and help identify the more obvious culprits that can adversely affect a Mac's performance.
Did this help you? Where can I buy the memory cards
