SLI Performance Increase question: How much will it help? BF3, Witcher 2 Etc.

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koomba

Limp Gawd
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Nov 10, 2004
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I've got a question regarding SLI. Specifically, how much it will help in newer games which use a lot of VRAM, in particular BF3, but also other titles such as The Witcher 2 and others.

I understand that with SLI, you still only have the amount of VRAM on one card available for the game to use. In my particular case, I currently have one GTX 570, so that would be 1.28 GB. Most games run fine, and BF3 runs good with a combination of High/Ultra. But when I start cranking up AA and AF, it slows down in some scenes, particularly large wide open areas. Having AA/AF is pretty much a requirement for me, it just really makes the visuals much more appealing, IMO.

Now I'm only running at 1920x1080, and it seems the general consensus is that a 1 card solution should be adequate for this resolution, correct? I realize I don't have the top card, the 580, but I know a 570 isn't that far behind it. So my basic question is: would adding a second 570 to go SLI help me? Would that allow me to run BF3, etc with AA/AF and get better performance? Or am I going to run out of VRAM anyways, and then still get unsatisfactory framerates? I'm not trying to run all Ultra, High is for the most part okay for me, but I really want to have good AA/AF. The jaggies just drive me insane.

I would really like to go this route if I could, I know a lot of people say SLI is a hassle, but it is the cheapest option for me. I could go the single card route, but if I remember right, a 580 is only 10-15% faster anyways, so SLI should give a much higher performance increase, correct?

I can get another 570 used for ~$275, and a 580 new is $500. Say I sold my 570 for $250, I could get a 580 for basically the same net price, but I can't afford the $500 up front, so I would be without a card until I could sell mine and then purchase the 580. That really isn't an option for me. Even if I went used, at say $400, it would only cost me $150, but I'd still have the issue of having to sell my card first.

So the short version is: Will 570 SLI vs just 1 GTX 570 allow me to run BF3 and other demanding games with better levels of AA/AF and/or at better framerates, or will I run out of VRAM in both situations anyways? :confused:

Thanks for the help.:)
 
gtx 480 sli
At "stock" ultra settings i am maxing out my 1.5gb vram, and thats without forcing crazy amounts of AA. might be better off holding out for something with some more VRAM
 
Get another 570. It's a better option than a single 580 in terms of performance.
 
For your purposes going SLI with another 570 would be better then selling and going with a single 580; 570->580 isn't a big enough jump. It's not like going from two 8800GT's to a single GTX280 or similar. So in your case SLI is about the only option if you really want better performance.
 
if your trying to run maxed out settings in multiplayer your probably still going to run into VRAM issues due to AA. i recall someone testing VRAM usage and in multiplayer it can get up to 1.5 GB with maxed out settings.

in all honesty i would never run deferred AA on multiplayer personally because the process introduces input lag and input lag on multiplayer FPS is just as bad as having a higher ping and to some people its worse because they can feel the delay. the amount of lag depends on many factors but mainly gpu power and VRAM is a factor because if you don't have enough its worse than not having enough power to perform AA fast enough to keep the game above 60 fps and that is key to making sure your video card is not what is causing input lag, getting less than 60 fps means its taking your video card(s) and/or CPU longer than 16.6 ms to render a complete frame, once you get down to the 30 fps area your at a pretty large handicap to other players getting high frame rates simply because for every frame you see they are seeing 2 frames! :)
 
I went from a single 570 to SLI and I am very satisfied. I too was worried about the VRAM issue, however, my FPS for bf3 near doubled and didn't seem like vram was holding it back because those two cards in tandem have so much horsepower. Now, I can't say the same about a more poorly coded game. Bf3 seems to be very well done. Even though the game is maxing out both my 570s vram, I'm getting stable fps, averaging 80fps outdoors and 120+ indoors, 4xaa, all ultra.
 
Frito said:
if your trying to run maxed out settings in multiplayer your probably still going to run into VRAM issues due to AA. i recall someone testing VRAM usage and in multiplayer it can get up to 1.5 GB with maxed out settings.

in all honesty i would never run deferred AA on multiplayer personally because the process introduces input lag and input lag on multiplayer FPS is just as bad as having a higher ping and to some people its worse because they can feel the delay. the amount of lag depends on many factors but mainly gpu power and VRAM is a factor because if you don't have enough its worse than not having enough power to perform AA fast enough to keep the game above 60 fps and that is key to making sure your video card is not what is causing input lag, getting less than 60 fps means its taking your video card(s) and/or CPU longer than 16.6 ms to render a complete frame, once you get down to the 30 fps area your at a pretty large handicap to other players getting high frame rates simply because for every frame you see they are seeing 2 frames! :)
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Thanks for the input, I never really realized that it affected you in the same way as ping. I had never really thought about it that way before.

But no, I'm not expecting to be able to run it all on ultra, it is more high than ultra, but still a mix nevertheless. And I'm not expecting to be able to crank the AA/AF all the way up or anything, but right now I can run low-med FXAA, but that is about it.

But thanks for all the replies, it sounds like it would be worth my time to go SLI. That is what I was hoping to hear, sounds good to me. :)
 
koomba said:
Thanks for the input, I never really realized that it affected you in the same way as ping. I had never really thought about it that way before.

But no, I'm not expecting to be able to run it all on ultra, it is more high than ultra, but still a mix nevertheless. And I'm not expecting to be able to crank the AA/AF all the way up or anything, but right now I can run low-med FXAA, but that is about it.

But thanks for all the replies, it sounds like it would be worth my time to go SLI. That is what I was hoping to hear, sounds good to me. :)
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you should be fine then. i have 2x 560 Ti's in SLI and the same CPU as you and just this morning did some benchmarks for a different reason but you can see my settings and performance in that thread here with 2 570's i'm sure you could pull off higher settings and still get the same performance i am getting.
 
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