PCGH: Micro stuttering on multi GPU solutions

[foxmino]

Is the clear line scrolling down the monitor in some games the same thing as the stuttering issue or is this a v-sync problem?

[realsmasher]

well, that's a good question.

if you keep in mind, that the frame from the second card comes close after the first, this "line" should appear much more often if there is micro stuttering.

but anyway, you can avoid it with v-sync.(the line, not the stuttering)

[Jungle+=]

Hello !

this thread is right up my alley....sadly
I'm experiancing the symptoms of stutter and fps drops of 50% back to 100% fps in 1 second cycles. The odd thing is that they stuttered when I first installed them with my water cooling. Upon fiddling with the waterblocks on the gpu's....and hence the cards themselves...I found that the stutter disappeared. I could still SEE stutter visually althought the fps remained near 100% of potential ( minor and playable ).

Well things were running almost acceptable ( with UT3 )...but I needed to clean out the water in my cooling as I'm still learning the nuances of keeping the loop clean.
Once again...upon reinstalling the blocks and cards....the horrible stutter. This time, fiddling some more with the card seating did not fix it. I gave up and reformatted the whole darned computer. With the new install of Vista Ultimate x64 and ATI's 8.2 drivers, the stutter was back to normal amounts ( double the fps of 1 card...just less smooth than 1 card ) I was almost happy ! 8-0

Well here we are again,with the final reseating of the waterblocks. Cpu never goes higher than 40 degrees at 100% load and gpu's at max load stay below 45 dgrees.
The massive stutter returned, this time with the visual cue of the fps dropping to exactly 1/2 and back to a full 2 cards output in 1 second cycles.

I have used the 8.2 drivers for both the balanced fps result ( less stutter , NOT stutterless ) and the wildly fluctuating fps. The only difference was actually touching the cards....or reinstalling the drivers and OS. ODD,,,,very odd

I even tried the Vista multiple gpu hotfixes that address the issue of windows desktop manager not alloting data to the second card properly....to no avail.
Hopefully they might help others with the stutter. Here they are...

KB945149-Multiple GPU Hotfix
KB945149

KB936710-DX10 & Multiple GPU Hotfix
http://www.microsoft.com/downloads/d...DisplayLang=en

KB940105-Virtual address space usage in Windows game development Hotfix
http://www.microsoft.com/downloads/d...DisplayLang=en

Hope they help some.

4 generations of crossfire later, I`m still waiting for ATI to write a comprehensive guide on crossfire use , not to mention a driver that delivers on their promise.
Shameful....in any other industry, the consumer protection agencies would get involved.

1 question about powerplay...from the ATI help files that load with CCC...it states " .PowerPlay™ for mobile computers manages the power requirements of the GPU by optimizing the graphics settings for higher performance or longer battery life. Use PowerPlay™ to balance performance and power consumption".
Is this why I can't find any settings for Powerplay like like I am supposed to, under the "Graphics Settings Tree"(ATI's description) ? I'm definately not on anything mobile ( the CoolerMaster Cosmos case weighs 35 Lbs. when empty) I only see a reference to PowerPlay in my Power Options...with a greyed out menu for settings.

Edit: A great article on micro stutter with multiple gpu's from a German site (pre translated for your convenience )
http://www.pcgameshardware.de/?article_id=631668

[saaya]

Edit: A great article on micro stutter with multiple gpu's from a German site (pre translated for your convenience )
http://www.pcgameshardware.de/?article_id=631668

this is the article this thread is about! :P

tombman, in the thread on 3dc you said that the hl2 integrated frame limiter already fixes this problem?
can somebody check this? does it just delay frames or does it really help to get more stable fps?

[Jungle+=]

this is the article this thread is about! :P

Blushes......
Now I remember where I first found it !
Methinks that 2 days without proper sleep wrestling my watercooling loop AND subsequent crossfire issues...has made me delerious !

[saaya]

interesting... i read the entire thread and maaaaannn, its full of kids insulting each other and stupid ego battles... geez...

so in the end, it seems some ati driver dev took the time and wrote a little tool that constantly stalls one of the gpus to keep the frame times of both gpus exactly in sync. the tool was removed since he uses a microsoft dll and either never received a reply from microsoft about using it, or received a reply telling him to stop distributing the dll.

is this the tool?