Nvidia SLI - Possible big framerate improvement.

Discussion in 'Technical Archives' started by ForthRight, Jul 18, 2013.

  1. Patterik

    Patterik Registered

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    I'm running 320.49 690 nvidia surround @ 5900x1080. After some quick laps this seems to be working great. Thanks.
     
  2. Ricknau

    Ricknau Registered

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    Son of a biscuit! This is the first thing ever proposed that has made my SLI be better than one card! Thank you ForthRight for discovering this! Using my current settings at Silverstone I get FPS of mid 30s with one card, mid to low 20s with old SLI, and mid 40s to low 50s with these new bit settings.

    That's 35ish percent gain. I'm stunned! GPUs went from 55% usage to 85%. That's with 15 AI (60s F1) in front of me at 4320x900 res.

    Thanks again ForthRight!

    Man let's go racing!
     
  3. Ricknau

    Ricknau Registered

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    Well... my enthusiasm is dampened. :( While the new SLI compatibility bits undoubtedly help at Silverstone they do not help at the other tracks I use for testing, namely Malaysia and Portugal. At these tracks my SLI performance matches but does not exceed my single card performance. And it is not as consistent or smooth.

    At these tracks my GPU usage is balanced but running around 60-70% and rides up and down a lot. Not the almost straight line 85ish% I got at Silverstone. And a peculiar thing happens at Portugal. At three or four places on the track the GPU usages instantaneously switches to a much lower level. Then it just pops back up to the previous level after a couple hundred yards or so. And to state the obvious, the FPS is directly tied to GPU usage. The graphs can be overlaid on each other. FPS at these "drop zones" can drop from 90s to 30s. The GPU usage in these zones with one card is straight line. :confused:

    I can understand that certain areas of a track would be a heavier load on the graphics processor but with my limited knowledge of 3D modeling and rendering I can't understand why the GPU usage level would drop out. Seems like it would keep cranking even if it couldn't keep up.

    Still thanks though to ForthRight for digging. You have more gumption than me. I am still of a mind to make my next card a top end single GPU one.
     
    Last edited by a moderator: Jul 19, 2013
  4. F1Fan07

    F1Fan07 Member

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    This compatibility setting, while helping some, isn't a universal fix. On my system I'm at about 100-130 fps leaving the Silverstone garage and driving to the track with the default compatibility and the bits posted months ago. With the recommended bits in this post my framerate drops to 25.
     
  5. zim2323

    zim2323 Registered

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    I have tried all the bits, original, ISI recommended and these. No change for me except a 10-20fps increase in single screen with the ISI recommended bits.

    ASUS Rampage IV Extreme
    i7 3930k
    64gb RAM
    3x GTX 680 2gb (2 in SLI, 3rd as an accessory card for my 4th and 5th monitors)
    OS on SSD and rF1/rF2 install on another SSD (both OCZ Vertex 4's)

    Configured with 3 monitors in SLI 2D surround on the 1st 2 cards

    rF2 Sebring (SCES) 10pm night with 5 AI, 3 headlights
    2xAA, 2xAF, no supersampling
    GPU's run at about 40-60% max when rF2 is run in Multiview.

    0x02402005:
    1920x1080=99fps
    5760x1080=26fps

    0x82482005:
    1920x1080=115fps
    5760x1080=26fps

    0x00500005:
    1920x1080=90fps
    5760x1080=26fps
     
  6. Gonzo

    Gonzo Member

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    The only solution is currently to disable road reflection and environment reflection.

    That bit here causes sli to not work anymore, disabled sli gives you more performance
     
  7. zim2323

    zim2323 Registered

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    I have SLI enabled in both screen res. Newer Nvidia drivers have the ability to not use the side monitors when not required per screen res, and those turn off when switching to 1920x1080.

    I'm not sure what I'd get disabling SLI entirely and just using a single card.

    And I do have road and environment reflections off, FYI.
     
  8. Rob Berry

    Rob Berry Registered

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    Is this for multi monitors only, or can I try these settings with my GTX650 and single 40 inch LCD @ 1920X1080 60hrz?
     
  9. Hedlund_90

    Hedlund_90 Registered

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    It's not for multi monitors only, but for multi-gpu's (SLI). You're on a single card (?).
     
  10. ForthRight

    ForthRight Registered

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    This surely can't make sense though - I get a lot more fps if I use that bits setting (with SLI enabled through my drivers) than I do if I disable SLI on my system. If I disable SLI it nearly cuts my framerate in half, so that suggests to me SLI is working, even if it isn't perfect. Both GPU's are working at near 100% with that bits setting too.

    It's a shame it isn't working for more people though. :(
     
  11. zim2323

    zim2323 Registered

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    I haven't tried recently, but on older drivers several months ago, using only 1 monitor on only 1 card, SLI disabled (bridge removed), I was able to hit over 300fps with default settings and NO additional changes. I think the minimum I saw was 220 in heavy use.

    My frame rates are cut almost in half with SLI. Add my 3rd card for tri-SLI in the mix and it got worse. It effectively scaled my FPS down from 300 with a single card single monitor, to 100-125 with dual-SLI single monitor, to 50 with tri-SLI.

    Would be really nice if ISI would take some time and focus on getting this part of the sim working properly. I hate running single screen when I've got 2 monitors sitting there wasting away.
     
  12. Ricknau

    Ricknau Registered

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    I get better FPS from physically removing second card rather than just disabling it.
     
  13. Ricknau

    Ricknau Registered

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    I posted this yesterday in the dead thread about negative scaling:

    For anyone who thinks there is some big step to be done by ISI to improve SLI I can tell you that that won't be coming. I've corresponded with Jeremy Miller and he states that their testing shows 95% GPU usage and that there is not much sense in them spending a lot of time trying to eek out that last 5%.

    I guess their testers must be in the "lucky" group who get good results. What a shame so many of us wasted our money on dual cards.
     
  14. zim2323

    zim2323 Registered

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    Yeah, maybe if we were actually getting 95% utilization. I see at MOST 60% using SLI. Even less in 2D surround. Bug fix please!
     
  15. zim2323

    zim2323 Registered

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    Ok, finally got around to trying something different. I isolated 2D Surround (triplehead/multiview) to a single card. I ran into some issues initially because I still had all 3 GTX 680's installed, but removed the tri-SLI bridge. The problem I had was that I could not select or configure Surround because it was grayed out. I had to remove 2 of the cards first, then configure, then add the 2nd card back in. I left the 3rd card out as I have no need for it.

    Below are how my tests turned out.
    SLI: rF1 - 5760x1080 - VHR2013 - Indianapolis - 225fps
    single: rF1 - 5760x1080 - VHR2013 - Indianpolis - 385fps

    SLI: rF2 - 5760x1080 - C6R - Sebring 10:00pm, 15 AI - 26fps (unplayable, still photo-like)
    single: rF2 - 5760x1080 - C6R - Sebring 10:00pm, 15 AI - 50-70fps (very playable)

    I'm very happy with the results of a single card of multiple cards. I only have the 2nd card installed to use my 2 extra monitors. I'll be selling all 3 of GTX 680's and getting a Titan at this point. I'll buy another cheaper DX11 card to handle Physx and Accessory monitors.
     
  16. C3PO

    C3PO Member

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    Do a search for the relevant bits configuration in nVidia inspector to properly activate SLI in rF2. I'm getting 59 FPS at Silverstone in cockpit at the back of a 20 AI grid of Corvettes, rising to 105 FPS elsewhere on the track. Usually it is around 70 - 80 fps. Running 2 x GTX 680 cards.
     
  17. zim2323

    zim2323 Registered

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    What resolution?
    Multiview?


    I've already done all of those. I've tried default, ISI, the 0x00500...or whatever bit. Tried every setting under the sun. My cards never use more then 40-60% utilization when running SLI in Multiview. If I run 1920x1080 in SLI (single monitor), then I see pretty good frames, but honestly, a single card at 5760x1080 was just as smooth as SLI on single monitor at 1920x1080 with almost half the frames.

    Single cards for me from now on. The only reason I started doing SLI in the first place was with the GTX 580's as it was required to do 2D surround. Now, with 2D Surround capable on 1 card, I'll stick with non-SLI until I see benefits in what I use it for.
     
  18. zim2323

    zim2323 Registered

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    I should also add, my 40-50 FPS was back of a field of 15 AI at 10pm at night (headlights) at Sebring, as a worst case. Most other day tracks I'm getting between 125-200fps with 5 AI and sunny.
     
  19. C3PO

    C3PO Member

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    5760 x 1080 - multivew off. My GPU utilisation is around 95% on both cards.
     
  20. zim2323

    zim2323 Registered

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    There's your problem. As I've stated, I have Multivew ON. You can turn Multiview off, but it makes the screen look stretched and ugly. I want 2D surround, not a stretched picture. I guarantee you won't get more then 25-27fps if you turn Multivew on.
     

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