SLI / Crossfire

[prok]

Does anybody uses this technology?

Does it make sense to DCS?

Thanks :)

[-Rudel-]

Matt mentioned in an interview that DCS doesnt take advantage of it. You could still dedicate one to PhysX if you ran 2 cards in SLI.

[Quirkitized]

SLI Works, just don't expect 100% scaling, and it pretty much only benefits in full-screen mode with DCS. I notice anywhere between say 15-70% scaling. That may sound like a lot, but it can mean only an extra 5 fps or an extra 30 fps, all depends.

 

I made a post about it here:

http://forums.eagle.ru/showthread.php?t=99637

 

You can do other searches, but people have decent results with SLI in DCS. Crossfire, never tried but I have read it's pretty much 0% increase, if not making it worse.

[prok]

SLI Works, just don't expect 100% scaling, and it pretty much only benefits in full-screen mode with DCS. I notice anywhere between say 15-70% scaling. That may sound like a lot, but it can mean only an extra 5 fps or an extra 30 fps, all depends.

 

I made a post about it here:

http://forums.eagle.ru/showthread.php?t=99637

 

You can do other searches, but people have decent results with SLI in DCS. Crossfire, never tried but I have read it's pretty much 0% increase, if not making it worse.

 

Well, thanks a lot for useful information. +20 FPS is really not bad for DCS.

 

Also interesting about CrossfireX exactly, because I'm ATI/AMD customer.

Really I be the first? :)

Very interesting to know at least one test.

[P1KW]

If things have not changed, Crossfire negative scale.

If you have a multi-monitor configuration, which necessarily go windowed mode, crossfire, auto-off.

I do not know if this is solvable with SoftTh.

If I get time off, this weekend will do tests with a 6970 and a 6990 full-screen mode and put the results here. With my 4 monitors settings in Windows extended mode, the result is identical in both, since I have to use the window mode.

 

Greetings!

 

PS: Maybe with EDGE, all this change, but would not bet a good vodka.

[SkateZilla]

SLI Works, just don't expect 100% scaling, and it pretty much only benefits in full-screen mode with DCS. I notice anywhere between say 15-70% scaling. That may sound like a lot, but it can mean only an extra 5 fps or an extra 30 fps, all depends.

 

I made a post about it here:

http://forums.eagle.ru/showthread.php?t=99637

 

You can do other searches, but people have decent results with SLI in DCS. Crossfire, never tried but I have read it's pretty much 0% increase, if not making it worse.

 

SLI/XFire only work in Fullscreen mode on any application.

 

DCS is not coded to use Multiple GPU Threads,

 

You can Enable XFire/SLI and go through ever profile, you will never get 90-100% Scaling on both GPUs, at most 60/50 or 60/60 scaling in extreme cases, because the engine wasnt coded to use more than 1 GPU thread.

 

SLI will naturally Present the illusion of better results over XFire, Simply because DCS Runs better on nVidia Cards to begin with. but a 10-15% Increase is well below "Working SLI" ranges.

 

If SLI/XFire was working correctly, you should see roughly 60-75% increase in most cases, and up to 95% on Extremely good cases (ie Battlefield 3)

 

 

 

as For AMD, i've tested Multiple Profiles, and never seen above 60/60 Utilization, and LOWER Frames/sec in some situations.

Edited March 20, 2013 by SkateZilla

[TZeer]

I have used 2 x 580 GTX in SLI for a while. In my case I can say that I have had a pretty good increase in performance over a single card.

 

Both cards at about 90% usage at the most.

[SkateZilla]

Which profile are you using?

[Quirkitized]

I have used 2 x 580 GTX in SLI for a while. In my case I can say that I have had a pretty good increase in performance over a single card.

 

Both cards at about 90% usage at the most.

 

Same here, been using two 580s for two years now and it's been great. When I first had them, DCS SLI performance two years ago wasn't very good, it's improved a lot, it at least works now to give some gains rather than nothing at all. I remember back when you'd get about 10%, now you can get up to 10-70~80%. They even solved the artifacting with the TGP/MAV, no need for nvidia inspector changes and loss of performance. Still get it on the mirrors, but don't use 'em.

[TZeer]

I guess the default DCS: Blackshark profile? I never messed much in the nvidia settings. Only turning SLI on and off.

 

But from a lot of testing with different settings, there are certain things that can drag down the SLI performance. Which in certain circumstances are bugs in my opinion. In other cases it's basically CPU bottleneck.

 

As long as you are not hit by any of them, the scaling is very good with SLI.

[P1KW]

I confirm that Crossfire negative scale with the latest version of DCSW.

 

Although the machine is modest and does bottleneck in the CPU this has been the behavior of a 6990:

 

Take off Beslan, full screen (Crossfire ON).

 

Crossfire Mode:

-Off: 33 FPS

-Default: 25 FPS

-Compatible with AFR: 25 FPS (ABRIS and Skhv flash)

-Optimize 1x1: 25 FPS

 

 

Identical, in windowed mode (Crossfire OFF), 33 fps.

 

Greetings!