Downsampling: How to

Discussion in 'Videocards - NVIDIA GeForce Drivers Section' started by wasteomind, Jun 17, 2011.

  1. andressergio

    andressergio Master Guru

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    i been testing and all works as a charm, only darker pic but more defined colors

    cheers !
    Sergio
     
  2. eiren

    eiren Active Member

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    Thanks for this!

    Been using it since you posted it, and has looked lovely. More often than not now, I can just turn off AA and it is all being supersampled by the downscaling... looks excellent.

    It means you can have things effectively supersampled without the huge GPU overhead :banana:
     
  3. Noisiv

    Noisiv Ancient Guru

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    Why would you prefer this over large array of normal AA modes? When they are available that is.

    It's far from "supersampled without the huge GPU overhead". It's as brute force as it gets.

    Me, of all the games I own, I'd use this in GTAIV only. I see it as possibly usable in couple more games: BFBC2, maybe Mafia 2 but not really :)
    It would be weird to use this in HL2 for example, as there are tons of other preferable methods.

    Most of UE3 games (dx9 ones) have no real AA, but do offer some AA,
    and I'm just not comfortable with running my monitor out of spec, as too many things can go wrong. Also I have a hunch my Samsung wouldn't go very far.

    2560x1440 over 1920x1080 just wouldn't cut it for me, if there are no other AA methods to begin with. And if there are...u get the picture.

    All on all great article. I always thought you need to edit EDID or something. Though more educational then practical.
    Except if you can double your native resolution, and don't mind the risk.
    2x2 is nothing to sneeze at.


    EDIT:

    3840x2160 was a no-go. Had to hit hard reboot couple of times. Managed to corrupt some of my files and settings:) Settled for 3200x1800.
    All in all cool thing if you have the GPU power / VRAM to spare

    [​IMG]
    http://alturl.com/d7j38


    [​IMG]
    http://alturl.com/mfenz
     
    Last edited: Jun 23, 2011
  4. andressergio

    andressergio Master Guru

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    yes same for me but 3200x1800 is it for 16:9 or 16:10 ?
     

  5. Noisiv

    Noisiv Ancient Guru

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    3200/1800 = 16/9 :)


    The difference is the same as between playing at lower and higher resolution.
    No more - no less.

    Hahahha the jealousy of it.

    Remember, the idea here is to enhance the picture quality, not blur the crap out of everything.
     
    Last edited: Jun 23, 2011
  6. andressergio

    andressergio Master Guru

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    nice man will try that as the other is no go as you

    cheers !
    Sergio
     
  7. eiren

    eiren Active Member

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    As I said, it's supersampling without as much GPU overhead that works in all games. I would still apply a small amount of AA though in most cases, especially for transparency AA.

    However, there's little point if it's all being supersampled by the downscaling anyhow?
     
  8. SamW

    SamW Master Guru

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    Isn't this just SSAA or whatever? Actually it is a little worse since you would be using a regular grid of sampling points which makes it kind of worse.

    I don't think it is anymore efficient than regular super sampling. I mean to get 2x anti aliasing on 1920x1080 you will render from 3840x2160 and down sample back to 1920x1080.

    Well I guess it is faster because from your example you get the equivalent of 1.33x SSAA which is quite a bit fewer samples per pixel than 2x.

    Actually why don't they graphics card drivers allow fractional sampling and blending with SSAA?
     
  9. Psycho101

    Psycho101 Master Guru

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    It is indeed a brute force form of OGSSAA. SGSSAA would offer better image quality over all and RGSSAA (no recent card on the market currently exists that can do Rotated Grid) would be the ultimate form of AA in terms of IQ.

    I can see it being slightly more efficient than nVidia's own OGSSAA modes and their hybrids (accessed via nVidia inspector) purely because no further driver intervention is required. However the performance advantage would vary by game and in most cases won't be very large.

    The only tangibe advantage to it is in games that are impossible to AA any other way, or that have severe disadvantages from forcing AA. One could also argue that in games that do support MSAA which have noticable peoblems with shader/specular aliasing, downsampling would be usefull too.
     
  10. eiren

    eiren Active Member

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    Found a real issue/bug with this, and have no explanation as to why this is happening.

    I have a custom resolution of 2498x1404 setup and being scaled down to 1080p.

    I have noticed recently that whenever I am playing a game or watching a film on my computer, that my internet speed slows down to almost nothing. This is including any other devices that are on my wireless network which just directly connect to my wireless router and don't touch the computer that runs the games and films.

    I have a 50MB cable connection, so normally it's rocket fast.

    When I was playing a game on my computer, I could run a speedtest.net test and I would suddenly go down from 45Mbps to 0.01Mbps.

    I tried everything to find the issue, and in the end... it was simply changing the resolution would instantly give me back all that bandwidth. I could run the speedtest on my laptop, and as soon as the resolution changed on my PC... it either made the internet very fast, or it slowed it down to nothing.

    Anyone else come across anything like this?

    I honestly have no idea how a custom resolution could be causing issues with a connected wireless router?
     

  11. Raiga

    Raiga Maha Guru

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    Last edited: Jul 22, 2011
  12. Raiga

    Raiga Maha Guru

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  13. Grahf

    Grahf Ancient Guru

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    I came to this conclusion after *months* of poking around the German forums, toying with downsampling and SGSAA, etc. Regular SSAA forced via Nvidia Inspector is simply better.

    I've yet to find a game where downsampling looked superior to forced SSAA, even in games which didn't support it.

    The German fellows I spoke to swore up and down that this was the case, but it simply isn't so IMHO. I had a thread going in the PC Hardware (de) forums where I even posted side by side screenshot comparisons to prove it (Mass Effect 2)

    In my experience, SSAA forced via Nvidia Inspector eliminates jaggies better than downsampling+SGSAA or SGSAA alone...
     
    Last edited: Jul 21, 2011
  14. rewt

    rewt Maha Guru

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  15. Raiga

    Raiga Maha Guru

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  16. Noisiv

    Noisiv Ancient Guru

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    ezy ... I use it in all Source games cept TF2

    and a pinch of TrSS :)

    [​IMG]
     
    Last edited: Jul 21, 2011
  17. rewt

    rewt Maha Guru

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  18. Noisiv

    Noisiv Ancient Guru

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    wrong answer :)
     
  19. rewt

    rewt Maha Guru

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  20. Psycho101

    Psycho101 Master Guru

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    It seems that you're confusing RGSSAA with SGSSAA.

    They're two totally different things.

    As for Down sampling or regular OGSSAA being superior to SGSSAA, I'm not going to even try to argue based on opinion and what "looks" better to someone else etc. If one looks better than the other, then use it by all means. However, looking at the sample patterns for both, downsampling/OGSSAA will not cover near horizontal and near vertical edges as well as SGSSAA and no where near as well as RGSSAA.

    Apologies for the incorrect statement in #29. I was talking within the remit of nVidia manufactured cards, but got carried away a little and forgot to emphasize that. :bolt:
     

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