Help! Games Unexplained Lagging

thetechdweller

Honorable
Dec 28, 2012
22
0
10,510
Hi, I wasn't sure where to put this. I need help. I got a gaming rig for christmas. Built it myself.
The parts I chose were great I thought I watched game play footage, benchmarks, the lot! But when I play alot of games they all suffer from this problem. The game runs fine at high settings 720p. At around 40 fps. Then after about a minute of playing it drops all the way to 10 or 15 fps. It plays at this for about 20 seconds then goes back up to 40. I have tried editing the settings, updating drivers ect it still has the same problem. It still drops to low fps when I am doing nothing on the game. This is the list of games it does this on that I have tried so far:

Chivalry medieval combat
Far cry 3
Sleeping dogs
assassins creed 3

Lots of other games play fine; skyrim, Dota 2, Portal 2 on highest settings 1080p. What I don't understand is why the games play fine, then drop to a ridiculous level. It is very puzzling and annoying as I know it is an alright rig and the games were expensive and I can't play them enjoyably. Here are my specs:

AMD FX bulldozer 8 core 8150 Stock cooler
MSI HD Radeon 7770 GHz edition
8GB RAM
500GB Hard drive
550w PSU bronze 80 plus
xigmatek case with 2 fans installed

I have been told that some of these games are badly optimized. This may be the case but both far cry 3 and sleeping dogs are partnered with AMD so that the games are well optimized. I hope it is not a problem with my CPU as it was £137. If you have any idea please leave a reply.

-Nathan