This seems to be a common problem among all my friends, and its stopping me from playing competitive completely.
My TF2 will be running at 60-90 fps, for an inconsistant amount of time to the issue, and then it will just drop to 0 and freeze for a random amount of time, worst i've ever had is about 15 seconds, and then I'll be dead.

I've tried putting my computer under like four fans and suspending it so it's cool, vaccuming the dust out or cleaning it with pressurized air. If it has to deal with game settings, I dont care what settings I have to play on, I just want to play 6v6.
Is this something I cant fix? or is it a common issue?
Would love any help or suggestions.
I run on DX81, config can get around 135.
This is my current computer, but I'll be buying a better computer purely to play TF.
http://www.samsung.com/us/support/owners/product/NP355V5C-S01US