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zim2323
04-20-12, 10:19 AM
I have 3 GTX 680's running in Tri-SLI 2D surround @5760x1080. I turn vSync off and have global Nvidia settings at 4xAA and 4xAF. I get around 40-50fps in pits and sometimes 70-75 on track.

I do not seem to really notice any problems with the lower frames at all, other then I get sick to my stomach because I can see the screen flickering.

I had the same problems in 2-way SLI 2D surround. The problem is that at certain pars of the track, especially with any AI cars on the track, I am seeing a severe "warp". The screens will go into slow motion, I can still hear engine and other cars, and then it will speed back up to the current point. It makes it really hard to be consistent on lap times and often causes me to wreck.

I have tried Megan, GT, and the 60's series and Mills and Monaco.

All the settings I originally set for performance were changed back (as far as I know), but I've had no incerease/decrease in FPS no matter what settings I ever changed. I'm worried I'm missing something, or possibly there's something I need to do in my particular case. I'm not sure who else is running a Tri-SLI setup in surround that could offer some advice.

I realize there may be valuable information I'm leaving out such as system specs, etc., so if you need more info, please just ask.

Thanks!

Bart S
04-20-12, 12:58 PM
OMG you have 3 gtx680s what on earth could you possibly need 3 of them for, it is well know fact that there is little gain to be had after 2 x 680. But people have mentioned before that 3 eliminates micro stutter but it doesnt seam so in this case. Are your framerates the same as with 1 card as with 3.

zim2323
04-20-12, 01:28 PM
I'm looking for input on the issue at hand, not debating your understanding of why I built the rig I did.

If you have information on performance issues, then please let me know. If you don't have a Tri-SLI surround setup, then all your doing is cluttering the thread.

Thanks!

As stated before, FPS is NOT the issue. I see the same "warp" whether I'm seeing 40 or 75 fps. The last time I tested a single card in non-SLI was build 60, and that ran without issue. It's an SLI surround issue. Again, I saw the same issues with 2 cards as I have 3.

I'd really prefer Tim, an Nvidia rep, or one of the other ISI Devlopers speak on this, as I would assume they would be the only ones that have any true information on this.

zim2323
04-20-12, 03:43 PM
I should also note, the same thing happened with my 2-way GTX 580 SLI surround setup and all of the R200 series drivers that I tried.

Kristoff Rand
04-20-12, 04:27 PM
you should buy a triplehead2go and watch your FPS double...

MrPix
04-20-12, 04:40 PM
I have 3 GTX 680's running in Tri-SLI 2D surround @5760x1080. I turn vSync off and have global Nvidia settings at 4xAA and 4xAF. I get around 40-50fps in pits and sometimes 70-75 on track.

I do not seem to really notice any problems with the lower frames at all, other then I get sick to my stomach because I can see the screen flickering.

I had the same problems in 2-way SLI 2D surround. The problem is that at certain pars of the track, especially with any AI cars on the track, I am seeing a severe "warp". The screens will go into slow motion, I can still hear engine and other cars, and then it will speed back up to the current point. It makes it really hard to be consistent on lap times and often causes me to wreck.

I have tried Megan, GT, and the 60's series and Mills and Monaco.

All the settings I originally set for performance were changed back (as far as I know), but I've had no incerease/decrease in FPS no matter what settings I ever changed. I'm worried I'm missing something, or possibly there's something I need to do in my particular case. I'm not sure who else is running a Tri-SLI setup in surround that could offer some advice.

I realize there may be valuable information I'm leaving out such as system specs, etc., so if you need more info, please just ask.

Thanks!

Have you done a default install of the nvidia drivers?

If so, try to uninstall all 3D Surround related parts of the drivers. I noticed your subject mentions 2D, but you did not say you had done a custom driver install that excluded the 3D portions (for 120hz monitors and nVidia 3D surround I presume)...

2068

I have 2 way SLI and 60hz non 3D monitors, so I do not install that part of the drivers and do not experience any stutter.

If you need more info on how to do it please ask and accept my apologies if you have already tried this, but as you mentioned you had the same problem in 2 way, I chipped in :)

zim2323
04-20-12, 10:25 PM
you should buy a triplehead2go and watch your FPS double...

I'd love to, and had one, but the ASUS VE258Q monitors I have would only do 60Hz at 1920x1080, and the TH2G is limited to 50Hz at 5760x1080. I can't do a lower res without screwing up the 4th monitor, because once the screen size changes, it throw off all the windows on the 4th monitor.

zim2323
04-20-12, 10:27 PM
Have you done a default install of the nvidia drivers?

If so, try to uninstall all 3D Surround related parts of the drivers. I noticed your subject mentions 2D, but you did not say you had done a custom driver install that excluded the 3D portions (for 120hz monitors and nVidia 3D surround I presume)...

2068

I have 2 way SLI and 60hz non 3D monitors, so I do not install that part of the drivers and do not experience any stutter.

If you need more info on how to do it please ask and accept my apologies if you have already tried this, but as you mentioned you had the same problem in 2 way, I chipped in :)

Yeah, I have done a full clean install with a full uninstall of everything first in Safe Mode with Driver Sweeper. I've tried for both the 301.10 drivers, as well as the 301.24beta drivers. I have not tried to uninstall or remove the 3D portions from the installation. I've only made sure that the 3D vision was turned off.

zim2323
04-21-12, 11:38 AM
I did get a response from Support, but it is mainly revolving around underpowered CPU. I sent them a screenshot of TaskManager, GPU-Z, and Precision-X all running on my 4th monitor while running rF2 with 10 AI at Monaco, and GPU never went above 70% load and CPU was never above 65%. I did boot into BIOS and made sure that Speed Stepping was still off/disabled.

Haven't tried with vsync on yet. I'll give that a shot today and see if that helps. Maybe there's something with SLI setups that require it???

bmwmaster
04-21-12, 12:07 PM
I have 3 GTX 680's running in Tri-SLI 2D surround @5760x1080. I turn vSync off and have global Nvidia settings at 4xAA and 4xAF. I get around 40-50fps in pits and sometimes 70-75 on track.

I do not seem to really notice any problems with the lower frames at all, other then I get sick to my stomach because I can see the screen flickering.

I had the same problems in 2-way SLI 2D surround. The problem is that at certain pars of the track, especially with any AI cars on the track, I am seeing a severe "warp". The screens will go into slow motion, I can still hear engine and other cars, and then it will speed back up to the current point. It makes it really hard to be consistent on lap times and often causes me to wreck.

I have tried Megan, GT, and the 60's series and Mills and Monaco.

All the settings I originally set for performance were changed back (as far as I know), but I've had no incerease/decrease in FPS no matter what settings I ever changed. I'm worried I'm missing something, or possibly there's something I need to do in my particular case. I'm not sure who else is running a Tri-SLI setup in surround that could offer some advice.

I realize there may be valuable information I'm leaving out such as system specs, etc., so if you need more info, please just ask.

Thanks!



Is it possible that your tri sli setup runs out of memory ?
Remember you have "only" 2 GB available with this high resolution and high AA activated you maybe need more than 2 GB. That could be the reason for the "warp". Your system at this time is loading data in GFX memory...............

zim2323
04-21-12, 12:09 PM
I have 3 cards x 2gb, so I have 6gb of video RAM available. Or are you talking system RAM? I have 24gb of system RAM, and Win7 64bit, so I'd have at least a 4gb program slices available.

I also don't have high AA turned on. I run at only 4x AA and 4xAF.

I'll try to turn those off entirely and see what happens.

zim2323
04-21-12, 12:25 PM
Ok...

Turned all AA and AF in Nvidia control panel and also in game. Seems a LOT better. Doesn't make sense though. I'm not even coming close to taxing either the CPU or the GPU's. I have a Rampage III Extreme and PCI's show at 16x8x8, so maybe that's the problem?

Any other ideas? I'd like to keep AA and AF on, as it really helps graphically. I wouln't have though this would be an issue given 3 cards and not maxing anything out.

otta56
04-21-12, 01:55 PM
The frame rate drops and stuttering you are experiencing are likely caused by the alternate frame rendering method used by all of the major video card vendors for multi-gpu acceleration. An explanation of the phenomenon can be found here: http://siliconmadness.blogspot.ca/2011/09/multi-gpu-thoughts-micro-stuttering.html Split Frame Rendering can eliminate the microstuttering, but at the cost of halving fps (from 60 fps to 30 fps) It will also cause the gpus to run hotter by 3-7 degrees celcius.

Workarounds:

The workarounds listed below require the use of Nvidia Inspector, a program to view and change the "hidden" parameters in the rF 2 profile not available through the Nvidia control panel settings. The program is available here: http://www.techspot.com/downloads/5077-nvidia-inspector.html

Change some of the settings in both the Nvidia control panel and in NVidia inspector for the rF2 profile to use the adaptive sync settings. The Nvidia control panel should be setup first then tuned for custom settings available only through Nvidia Inspector.
Nvidia control panel settings would look like this:
2078 2079

Next open Nvidia Inspector and navigate to the rF2 profile. Change the settings to look like this:
2080

The settings are based on my experiments with an SLI GTX580 setup to give a steady 60 fps at 6020X1200 (no shadows, no HDR, no FXAA, multiview, 25 AI, all other settings at max)

Using the adaptive vsync on the new Nvidia 301.24 drivers does help for 60 Hz refresh monitors.
Some minor stuttering is still evident, particularly in the pit lanes and around corners where there are buildings or trees. This is likely due to the way ISI implements render targets in the frame buffer. It seems to be inherent in multi-gpu systems from all vendors. It is particularly evident with shadows turned on. Information about this can be found in the Nvidia best practices programming guide available here:
http://developer.download.nvidia.com/GPU_Programming_Guide/GPU_Programming_Guide_G80.pdf

As always, your mileage will vary. Keep in mind that these settings are valid for rf2 build 69 and Nvidia 301.24 drivers only.

bmwmaster
04-21-12, 01:57 PM
When you are runinng 3 cards in Sli, you donīt have 6 GB available. You still have 2 GB available. My english isnīt good enough to explain further but you can find infos all over the net.

You should use a tool like gpu-z to display your GFX mem usage and then adjust your settings so that the usage donīt go above 2 GB.

Your Setup has massive rendering power, sadly the amount of memory of your cards might be to low to use the power.
So if you adjust the settings and fps are too high, i would try 2x SLi, if your then are happy with your FPS then just sell one card because it makes not much sense to run 3x SLI in that case.

zim2323
04-21-12, 02:10 PM
When you are runinng 3 cards in Sli, you donīt have 6 GB available. You still have 2 GB available. My english isnīt good enough to explain further but you can find infos all over the net.

You should use a tool like gpu-z to display your GFX mem usage and then adjust your settings so that the usage donīt go above 2 GB.

Your Setup has massive rendering power, sadly the amount of memory of your cards might be to low to use the power.
So if you adjust the settings and fps are too high, i would try 2x SLi, if your then are happy with your FPS then just sell one card because it makes not much sense to run 3x SLI in that case.

I was using 2x and tried 4x (worse), I now am running nothing. I would be curious to see how/why you think that the memory is not combined on these cards. My understanding was, as of the 400 series cards that memory would combine. Now I understand you can't utilize the full 6gb, but you can and do utilize a portion of the memory on the other cards. I think I remember reading something like 70-75% was still usable on the 2nd, and around 50% on the 3rd. (???)

Anyways, please post some more info on this, as everything I've read and tested has shown otherwise.

Also,
I have turned on vsync (software) in game and enabled adaptive in the control panel. I can now run 4x AA and AF with very little stuttering/warping.

I'm getting there!!

zim2323
04-21-12, 02:10 PM
The frame rate drops and stuttering you are experiencing are likely caused by the alternate frame rendering method used by all of the major video card vendors for multi-gpu acceleration. An explanation of the phenomenon can be found here: http://siliconmadness.blogspot.ca/2011/09/multi-gpu-thoughts-micro-stuttering.html Split Frame Rendering can eliminate the microstuttering, but at the cost of halving fps (from 60 fps to 30 fps) It will also cause the gpus to run hotter by 3-7 degrees celcius.

Workarounds:

The workarounds listed below require the use of Nvidia Inspector, a program to view and change the "hidden" parameters in the rF 2 profile not available through the Nvidia control panel settings. The program is available here: http://www.techspot.com/downloads/5077-nvidia-inspector.html

Change some of the settings in both the Nvidia control panel and in NVidia inspector for the rF2 profile to use the adaptive sync settings. The Nvidia control panel should be setup first then tuned for custom settings available only through Nvidia Inspector.
Nvidia control panel settings would look like this:
2078 2079

Next open Nvidia Inspector and navigate to the rF2 profile. Change the settings to look like this:
2080

The settings are based on my experiments with an SLI GTX580 setup to give a steady 60 fps at 6020X1200 (no shadows, no HDR, no FXAA, multiview, 25 AI, all other settings at max)

Using the adaptive vsync on the new Nvidia 301.24 drivers does help for 60 Hz refresh monitors.
Some minor stuttering is still evident, particularly in the pit lanes and around corners where there are buildings or trees. This is likely due to the way ISI implements render targets in the frame buffer. It seems to be inherent in multi-gpu systems from all vendors. It is particularly evident with shadows turned on. Information about this can be found in the Nvidia best practices programming guide available here:
http://developer.download.nvidia.com/GPU_Programming_Guide/GPU_Programming_Guide_G80.pdf

As always, your mileage will vary. Keep in mind that these settings are valid for rf2 build 69 and Nvidia 301.24 drivers only.

THANKS!!!

I'll work this into my testing. I replied in another thread that mentioned this but didn't see a response yet, as to how to do this. Now I can test this as well!

MrPix
04-22-12, 10:54 AM
My understanding was, as of the 400 series cards that memory would combine. Now I understand you can't utilize the full 6gb, but you can and do utilize a portion of the memory on the other cards. I think I remember reading something like 70-75% was still usable on the 2nd, and around 50% on the 3rd. (???)

Anyways, please post some more info on this, as everything I've read and tested has shown otherwise.

Taken from nvidias website on the SLI zone (http://sli.nvidia.com/page/slizone_faq.html#c1)....

Q. When I configure two graphics cards in SLI mode, do the graphics cards work together to create double the memory size?
A. No. In SLI mode, each graphics card uses its own frame buffer memory to render a 3D application. The operating system will report a graphics card frame buffer memory size that is found on a single graphics board.

I thought it was combined until I went triple screen, where I got 1st hand experience and unfortnately, found it wasn't!

I know I only have 2 way SLI, but still think it's relevant. I ran out of video memory on my 2x 580 1.5GB setup and started to experience stuttering (running at 5910x1200 BTW) and poor FPS on certain games/sims. I sold them both and bought 2x 580 with 3GB each and no longer ever run out of vram... I monitor it in real time and can vouch that it certailnly looks like it is mirrored card to card as the utilisation is ALWAYS identical. AFAIK, all SLI does is double the amount of CUDA cores to render graphics.

Some great explanations about SLI here (http://forums.nvidia.com/index.php?showtopic=158727) and has multiple references to the data being mirrored across the cards.

Bart S
04-22-12, 07:50 PM
I can honestly say I have come close to using the full 2gb on my GTX680 at 5920 x 1080 but all tracks so far are just below, I run with max everything apart from hdr and shadows medium and in online races fps is 35 lowest on grid and avg 55 - 60 going on to 80 at best.
It could be a possibility that a slightly higher res may use a little more but i notice u are at 1080 anyway.
EVGA precision X reports your VRAM usage, use that to see if you are hitting the limit.
It is also possible that sli may require slightly more vram to operate.
I run CSAA x32 and all is fine for me not tried less than x16q try CSAA x32 and see if its any better.
I notice a wider field of view also uses more vram but at my res in multiview I run all cars a 24 and its good.

Kristoff Rand
04-23-12, 04:50 AM
yeah from what I know or think... you only get the ram off the first card. you get the gpu's off all three and then those speeds depend on the speed of each slot. 16x8x4 etc.

that's why they make the high ram cards so much more I believe.

jonchard
04-26-12, 05:45 PM
Zim, will you try turning off environmental reflections .. it screws my dual 580's big time yet i drop to single card and the "warping" effects dissapear ... Let me know please!

Spyder
04-26-12, 06:09 PM
@Jonchard : I had that with my 580s and it's still there with my 680s.

jonchard
04-26-12, 08:16 PM
Thanks.

jonchard
04-27-12, 07:09 PM
Spyder, if you see this, my 3x24" experience of RF2 really sux!! I really want to see this game at its best, but i have to drop SOOO much by way of settings and niceties, that i may as well be playing pole position on the Spectrum (slightly over exagerrated - dont jump on me fan bois!) Do you have any advice to getting 5760+ running adequately? AI makes a fair amount of difference in my testing, as does shadowing, AA, etc Now my FPS can be as low as 20/30 on start grid and up to 100+ once clear or lagging pack, but as soon as i join Ai racers, i start to feel lag / warping. Are your 680s SIGNIFICANTLY better or just a bit as im expecting (I think SLi and triple screen is a little too soon for ISI - May experience of 3 screen racing on iRacing is utterly incredible ... but i want the 60's cars!) - I'll take any advice you can give.

Cristian Why
05-16-12, 05:02 AM
OMG you have 3 gtx680s what on earth could you possibly need 3 of them for, it is well know fact that there is little gain to be had after 2 x 680. But people have mentioned before that 3 eliminates micro stutter but it doesnt seam so in this case. Are your framerates the same as with 1 card as with 3.

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