I have reseated the RAM and the video card now. I dusted the video card off with a soft brush and cleaned out any dust I saw on the slot of the motherboard. Everything seems to be working well, there are no random lagging moments and the graphical glitches in Firefox haven't come back. They were starting to get worse and worse before I did this so I'm guessing the video card was a little out of place. The drivers should be correct, I have the MSI Radeon HD 7790 and I got the one specifically for the 7790: Link Removed
Thanks for all the help guys! Now I've learned a little more about what can cause these issues and I'm glad to have experienced it.
The above was my original draft. I just wanted to wait a few days before posting...