FX 8350 and 2 GTX 660's in SLI = Low GPU Usage and lower than expected fps.

nline24

Honorable
Sep 17, 2013
10
0
10,510
Hey guys.

I've spent a lot of time trying to figure this out. I am hoping someone might be able to see something that I am not.

Here's my setup.

FX 8350 at 4.3 Ghz
ASUS 990x MoBo
8 Gig GSkill Ripjaw at 1600
2x EVGA 660 non ti superclocked - SLI
TX 750 Corsair Power Supply
128 GB SSD
20 inch monitor at 720 p 1600x900

So I recently upgraded the motherboard to the 990x and added the second 660. I noticed an overall improvement in most of the games I play. I have been able to up the settings and keep a decent frame rate. Thing is some games still bog down into the 40's in areas where there is a lot going on. This doesn't seem right when my GPU usage is usually around 30-40 percent on each card. Sometimes as low as 15-20 percent on each card. Crysis 2 on Ultimate pushed the cards to the 50's and 60's percent. So overall even though performance has improved over just having one 660 it feels like something wierd is going on.

I am the kind of person that wants and needs a steady 60 fps lol. Seems like games shouldn't be dipping below 60 when I have so much room on the video card usage.

Things I have done. I updated the bios and chipset, the graphics drivers, audio drivers. I made sure all the settings in the nvidia control panel were set the way they should be for sli.

I have also ran ran 3d mark 11 and the GPU's both go above 95 percent usage during the video stress tests.

I am at a loss and I hope the great people of TH can help me out. Thanks in advance.
 
Solution
That sounds like you have covered most bases. Just to be sure that the system isn't bogged down with background tasks, check System Configuration/Start Up and see how many boxes you have checked.
Then run CCleaner to clean up resource wasting crap and registry errors. http://www.piriform.com/ccleaner

At 720p, you should be flying with those 2 GTX 660s. I have a pair of GTX 660 OC cards in the rig in my sig. And our processors should be fairly comparable when it comes to gaming.

What is your 3DMark11 score? I'll compare it to mine.

clutchc

Titan
Ambassador
That sounds like you have covered most bases. Just to be sure that the system isn't bogged down with background tasks, check System Configuration/Start Up and see how many boxes you have checked.
Then run CCleaner to clean up resource wasting crap and registry errors. http://www.piriform.com/ccleaner

At 720p, you should be flying with those 2 GTX 660s. I have a pair of GTX 660 OC cards in the rig in my sig. And our processors should be fairly comparable when it comes to gaming.

What is your 3DMark11 score? I'll compare it to mine.
 
Solution

clutchc

Titan
Ambassador


Darn. Just checked my Futuremark results. I hadn't run 3DMark 11 since I installed these cards. So I'll have to take the time to run it. But the 2 x HD 7870 OC cards I had in awhile back had a score of 11116, so you seem about right.

I can get back to you on 3dmark11 or you can run 3dmarkvantage if you want to take the time. I have results for that one.
 

clutchc

Titan
Ambassador
I just found my records of a comparison run I did with 3dmark 11 between the 7870s and the 660s. I didn't record it on the Futuremark site, but I saved the results for comparison when I was swapping cards around. My score with the rig in my sig was 11066.
 

nline24

Honorable
Sep 17, 2013
10
0
10,510
Yeah I think I was at like 10, 500 so not far off.

So basically, in video benchmark testing everything seems to be working correctly.

In actually playing games, the GPU usage is tanking.

At least that points me in some direction and eliminates some kind of a hardware issue or bottleneck.
 

nline24

Honorable
Sep 17, 2013
10
0
10,510
So I think I figured this out as far as knowing if my setup is working correctly. Just not sure how to get better performance with the certain games I am having trouble with.

I think the main culprit as far as low gpu usage is/was Vsync. I hate screen tearing so I tend to have every game capped at 60 whether through fps/triple buffering or a fps limiter.

Battlefield 3 for example capped with VSync runs at 40-50 percent usage on both cards. Without Vsync it runs as high as 175 fps with both cards at 99 percent. i'll take this as there being nothing wrong with my cards and setup.

But I still run into issues with certain games. Crysis 2 for example runs great on Ultra settings but certain areas it dips down to 45 fps and the cards arent being utilized over 50 percent. Regardless of Vsync on or off and whether I am running Dx9 or Dx11.

Sleeping dogs still never breaks 30-40 percent usage. I am assuming the game just sucks with sli.

So all in all, I am fairly positive my system is running as it should be. Just have to mess with settings on certain games to get a always 60 fps performance.
 
Unfortunately, you are probably experience CPU bottlenecking. While the CPU that you have can perform well, it only performs well when lots of cores are needed, but on games which push core speeds with fewer cores, it does poorly.

It may also account for your low 3Dmark11 score, though if you show the graphics score, that would be more telling.

Low GPU usage is a classic sign of a CPU bottleneck. If could even be the CPU is throttling due to too much OCing or power draw for the PSU.