I'm also running older games like The Witcher and Just Cause 2 at around 15-28 fps at any settings. Other games with simple graphics such as Age Of Empires III, are unplayable at max settings, and barely playable at the MINIMUM settings. I could play Dota 2 with max graphics at around 30-60 fps (then the winter map came out, can't play it at all, but that's a known issue).
I can't even run World of Warcraft at max settings over 25 fps. Playing Deus Ex: HR at max is also practically unplayable.
As far as i know this GPU should destroy all these games even at max settings.
Another thing to note is that overclocking it even by 10mhz cause immediate artifacts (looking like TV interference) all over the screen, which are usually remedied only by a reboot.
My system is pretty much brand new and its specs are:
Processor: Intel i7 2600k
RAM: G-Skill Ripjaws 4x4b @ 2133 mhz
GPU: This retarded XFX Radeon HD 6950 2GB
Motherboard: Asrock Z77 Extreme4
PSU: Corsais CX600
Case: Cooler Master CM 690 II
Windows are 7 Ultimate 64 bit, like the 5th fresh install so far, all drivers are up to date.
Also I didn't update the BIOS of the motherboard. I haven't flashed the 6950 to any other BIOS either, nor have I unlocked its shaders.
Off-topic smaller issue, just in case someone can answer this as well. My CPU is performing quite well, however it constantly underclocks itself, which is intended as far as I know. The problem is, though, that when it's clock is 4000MHz, it's at 50-60 degrees Celsius, but when it underclocks itself to anywhere between 1600-3400 it heats up to 90 degrees or so. I tried disabling speedstep and all the C states it still kept doing this.
First of all I'd suggest looking in catalyst control center at the 3D application settings.
Make sure all of them are set to application controlled, and turn things like morphological anti aliasing off.
Next, have you got both power connectors plugged in properly to the card, not sure if the system will even start without them, but double check anyway.
Since your saying that your CPU is overheating, the problem may actually lie with that and not your GPU.
Make sure you have a decent heatsink cooler attatched (the stock Intel one isn't really going to cut it if your gaming on that chip) and make sure you have enough thermal paste sat between your cpu and the heatsink.
You may always have a bad card, so it may be a case of RMA'ing it and getting a replacement.
I have actually done a motherboard bios update to the latest version just for the sake of covering everything, since I've done all the things you suggested multiple times. And believe it or not it fixed all my issues with the GPU, which is something I haven't expected at all.
I now only have 2 problems left, 1st one happens whenever i OC the card i get a mixture of flickering and artifacting whenever something moves on screen, this last for about 2-3 minutes and stops. The GPU then behaves completely normally (better than when not overclocked). It doesn't overheat nor artifact in anyway. I'm wondering if this is acceptable behavior or another problem.
The second problem is the CPU, which like I said isn't even overheating, it's just hot when it's idle, and at low frequencies (1600, 2000, those 2 usually). If it starts working seriously (which rarely happens considering the CPU is overkill for most things I do) it gets into the frequencies i designated for it (4000) and cools down to 50 degrees. This behavior is completely insane if you ask me and I have no idea what could be causing it. The CPU works perfectly other than that.
Thanks a lot for taking the time to reply, by the way