CPU bottlenecking GPU?

[jjzpgg]

So I'm relatively new to the world of overclocking (as will become apparent, no doubt). I recently picked up an MSI Radeon 7950 gfx card, and an Antec 750W PSU. I've got an ASUS M4A87TD/USB3 mobo and an Athlon II X4 640 processor. I used the auto overclocking function on my BIOS (probably my first mistake) which claims to OC my CPU to a stable 3.4MHz (CPU-Z confirmed this figure); I've also OC'ed my GPU up to about 90% usage but don't know how to get it any higher.

I ran a test on Heaven with this set up. All the settings on Heaven were ramped up to the max and I got a score of 834, and an average FPS of about 34. I then started playing Assassin's Creed 3 and within about 30 seconds got a BSOD and an error saying my CPU had overheated (no surprises there).

For someone who's recently acquired a new graphics card I'm seeing very little improvement in terms of FPS so I'm certain there's a problem somewhere, but where?

 

[EarthDog]

First of all... stop that overheating. The temperatures (found by using coretemp) need to be under 60C at load. It could be the CPU throttling b/c of temps. Once that is out of the way, try it again and see if you get 100% GPU use. I have to imagine that Athlon you want to push a little to let the 7950 stretch its legs. What resolution are you gaming at?

 

[bmwbaxter]

+1

Try running everything at stock speeds and post your temps then.

 

[jjzpgg]

First of all... stop that overheating. The temperatures (found by using coretemp) need to be under 60C at load. It could be the CPU throttling b/c of temps.

I've been advised to buy a cooler for my CPU, but if I'm going to do that I think I should get pick up a new CPU altogether! If my CPU can't handle being OCed to 3.4GHz then is it all just a waste of time? Or is there a way to get that speed without needing a cooling unit?

I'm gaming at 1920 x 1080.

 

[Trance4c]

I agree, take that CPU and GPU overclock out!

Then, start to the bottom, determine if your CPU really is a bottleneck. How to do this: Load up the most graphically intensive game you have, run FRAPs so you see your FPS and have it at the lowest resolution. This will tell you what your CPU limit is capable of doing. Then increase the resolution one step at a time until you see the FPS drop, then you know at what point your GPU is a bottleneck. If you can get to the highest native resolution your monitor can do and there is no FPS drop, then you have no CPU bottleneck.

Good luck.

 

[bmwbaxter]

I've been advised to buy a cooler for my CPU, but if I'm going to do that I think I should get pick up a new CPU altogether! If my CPU can't handle being OCed to 3.4GHz then is it all just a waste of time? Or is there a way to get that speed without needing a cooling unit?

I'm gaming at 1920 x 1080.

The heat is the reason you can't stablily run at 3.4

So a cooler is going to help a lot.

At the res you are running at the CPU is still a big factor.

What motherboard are you using?