7950 gpu usage problem--possible power issue?

tekhne

Honorable
May 31, 2013
7
0
10,510
Hi all,

Recently, as in back in May, I got a 7950 Iceq boost edition, upgrading from two 6850s. It's come to my attention that this card is underperforming in most cases. For instance, in Rising Storm/Red Orchestra 2, I can't break 60 fps and the gpu usage barely gets up to 50%. In Bf3, it fluctuates from 95% to 50% sometimes, dropping the frames from around 70-80 to 30-40, and making it basically unplayable. In all my games, gpu usage isn't in the 90's for most of the time, and usually sits in the 20-60 range. On a game like rising storm, I should be pulling probably over 100 fps on ultra with a 7950. On bf3, I should be getting at from 50-80 more or less constant. What gives? In certain games, like Guild Wars 2, which I also play, the gpu is vastly under utilized, same with Shogun 2, but with others, there's no excuse for the gpu usage being always in the 90's, right? What gives?

3.8ghz 965 BE with a Cooler Master EVO 2012 cpu cooler
630w Rosewill PSU
4gb Ballistix ram

I'm playing at 1920x1080


Here's what I've done so far.

Done a complete uninstall and reinstall of drivers
reinstalled windows
made sure the card is plugged in correctly
tried all sorts of clocks--when underclocked, the gpu usage rises a bit, but it still gives bad performance. when overclocked, the gpu usage sinks a bit. Tried raising the power limit as has been suggested.

The last thing I'll mention is that my computer sometimes has trouble starting up, and it's only with this card in, the 6850s work fine. Sometimes all i get is a black screen when starting up, and a reboot is needed... There's something weird going on with how my card is interacting with the other components, I just cant figure out what it is...

Thanks for any and all help guys.
 
Solution
I would try to log cpu usage as well at the same time to see if the cpu is causing a bottleneck at these times.

As an example in GW2 a large enough battle(world events sometimes) will case a increase in cpu usage and a drop in both frame rate and video card use. At those points, even 4.4ghz of i7 2600k can not feed the card fast enough.
I am not sure about all the games you have, but GW2 will jump from being cpu bottlenecked to gpu bottlenecked depending on the number of players and what is happening for sure.

How is the cpu load with these games?

Remember a game that only uses 2 cpus will look like 50%, but that could be a cpu bottlebneck. It would explain the fact that overclocking the card lowers usage and underclocking brings it up a bit.
 
GPU usage below 99% with VSync turned off is an indication of a bottleneck elsewhere in the system. It could be the CPU or the game itself not being very demanding. Basically, the lower your GPU usage, the more your GPU is needing to wait for the rest of the system to catch up.
 

tekhne

Honorable
May 31, 2013
7
0
10,510


Thanks very much for your replies.

I haven't checked my CPU usage but I know theoretically 3.8 ghz shouldn't produce this kind of bottleneck on a single 7950. On GW2, usage is closer to normal between 60-99. But all the other games barely break the 50's with GPU usage, and if they do, as in BF3, it isn't steady but goes all over the place causing annoying frame drops. Could it be a faulty card?


 

How's your FPS? Is it steady despite the usage spikes?
 

tekhne

Honorable
May 31, 2013
7
0
10,510
No, and this is the essential problem...fps is heavily affected. For instance, in BF3 90-99% 70-100 fps, 50-60%, like 38-50 fps :pfff: In GW2, however, the fps is generally more stable. However when testing other games --Rising storm, Witcher 2 for instance--the gpu usage never gets to the 90's
 
I would try to log cpu usage as well at the same time to see if the cpu is causing a bottleneck at these times.

As an example in GW2 a large enough battle(world events sometimes) will case a increase in cpu usage and a drop in both frame rate and video card use. At those points, even 4.4ghz of i7 2600k can not feed the card fast enough.
 
Solution