Memory for my Mac (only has 2 GB, going up to 8 GB). I see on my Activity Monitor that I have 2 GB of memory, while 1.96 to 1.98 memory is being used and over 200 MB of swap space is being used. I sure hope it makes my mac run faster (running on Yosemite on a 6-y-o iMac). It takes about 45 seconds to get to the desk top and over another two minutes before I have control of the Mac after launching FireFox, Mail, and Activity Monitor. Any program thrashes real badly, beach balling me for over a minute sometimes. In Mail, just to click on a message to read it again and get the message to load in the message window takes upwards of 30 seconds. It should be here in seven days.