I´d like to tell another story, which could be helpful for the community:
I experienced major FPS drops, too when playing games like civ5 which demands GPU and CPU as well. Usually (and now) this game runs constantly at > 60 fps. FPS were dropping after a few minutes to < 20. All temperatures I monitored (CPU, GPU, MB from Asus FAN Xpert 2) were quite just well (< 50° C, < 75° C, < 40° C). So I didn't think about a temperature problem. The same problem exists under an entirely new OS (Win XP x64). I tried several display driver versions as well.
So it seems that there were no indicators for this huge FPS drop! The only thing which catched my eye after some time was the power consumption of my graphic card (% TDP, GPU-Z). It falls partially beneath 25 %. So I thought: Could be the PSU. I´v never had any problems with that one so far.
But thanks to the post from is3 it dawned on me ... so many thx for the hint, dude!! Did take me weeks and dozens of threads to figure out!
is3 :
No, exactly. Processor was only symptom too. Motherboard was problem. VRM was overheating because it was build only for 95W processors and my is 125W. I changed motherboard to ASUS M5A97 Pro and problem is resolved. And also bought another fans to case.
Some weeks ago I was changing my inner workings of my machine and in the course of this I switched to an all-in-one hybrid hydro CPU cooler (Antec H20 620) - besides a turned of most of the case fans, because I love silence - In consequence of that the indirect cooling of the VRMs besides the CPU sockel dropped out and it seems that these little MOSFETs got to hot!
So my solution was quite simple: Open the case! (Or buy two NB-eLoops and build a strong air-tunnel respectively)
Lessons learned:
- Never turn of all your case fans
- Monitor ALL of your temps with an appropriate program like HWMonitor
(and know how to interprete them, especially the motherboard sensors, there are several ones)
- Begin by considering all possibilities (if u know them)
EDIT:
Random drops returned after a while
In the end after some more testing it turned out the graphic card is to blaime for all the hick-hack. I´ve tested that out with a new Gigabye GTX 670 OC and the issue ended in smoke ... so card goes back. Sorry 4 all the confusion
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CPU: Core i5 3550 @ 4.1GHz
MB: ASUS P8Z77-V
GPU: Gigabye GTX 670 Windforce 3X
PSU: Tagan PipeRock TG700-BZ
RAM: 2x 4GiB G.Skill RipJaws DDR3 @ 2133MHz 11 11 11 30
HDD: 2x Samsung 128GB @ Raid 0
CASE: Antec Twelve Hundred