Harddrive won't affect FPS unless you're playing games that actively load from the disk while playing, which TF2, CSGO, and DayZ don't.
You could be throttling from heat or something else, make sure power options are set to high performance in windows. Anyhow, Vishera cores in the AMD series CPUs aren't that strong individually so for games that still aren't optimized well to use all 8 cores, you'll probably get some FPS issues, likely in TF2 especially moreso during highlander or large pubs. Even 4th gen i5 dual-cores with an equal video card can beat it out in a wide variety of games released within the past few years.