Reinstallation of Windows killed performance

Hey guys,

I've searched and found nothing on the matter, so any help would be appreciated. I've had BeamNG for several months now, and it always ran great. Until I reformatted and reinstalled Windows 7 thinking I'd get a general performance boost from a clean file system. Apparently, I was wrong. My FPS is easily halved from where it was, using any given vehicle. Graphics settings make little difference as my framerate triples when I pause physics, indicating a CPU bottleneck. Increasing thread priority did nothing, neither did assigning BeamNG to specific cores (i.e. Core 3 which Windows 7 doesn't touch)

Hence the quandary: What, during a wipe and reboot of windows, would kill my CPU performance? BeamNG is the only game that seems affected.

The CPU in question is an AMD FX4100 (Save the AMD bashing. I know the Intel i series gives better performance but I built this system on a budget several years back and until now it's run BeamNG very well.)
Overclocked to 4.3GHz across all 4 cores, CnQ and all that garbage disabled. Stability confirmed and tested. It's been running this way for years. Neither the CPU nor the Northbridge run anywhere near thermal throttling. (30C under max rated temp.)
GPU is a GTX560Ti (older, yes, but again it ran just fine until recently and my problem is not GPU related.)
16GB DDR3, Raid5 HD array, SSD boot drive.

Thanks for any insight!

EDIT: If it helps, I'm now only seeing 30-40% CPU usage for BeamNG, whereas before it would use 80-85% of the available processing power... so something is definitely going on somewhere. I've also tried the core unparking solution listed in the forums and it found me about 2FPS.

 

I'd at least make sure drivers are up to date.

 

Just tried both the newest GPU drivers. Using the older drivers lets me enable FXAA with no performance hit (with physics off to test GPU load only), whereas the newest ones do not allow for program-specific hardware antialiasing (I refuse to use the GeForce Experience software) so I will stick with the older ones. Good call though, I hadn't thought of drivers. Thanks for the suggestion.

 

Yes they do, use the nvidia control panel not the geforce experience and you should find what you are looking for. As for the FPS hit that is very strange, maybe there is some other driver for something that was removed and is causing some weird issue but idk what it could possibly be.

 

I actually solved this at about 4am, and figured id post what I found in case this happens to anyone else. Steam was the issue. Running steam and clicking BeamNG = 14fps, tops. Running the BeamNG .exe directly = 35-40fps average. Tested using the Moonhawk on Industrial Site.