Quote Originally Posted by Oc-Ghost View Post
Secondary to primary frame buffer lag.. didn´t think it existed because of the bridge.
But then again thanks to serial connections, we have some lag.
Guess that´s the only edge parallel connections will ever have.
thats not it, you could delay the output of a frame to compensate for that, but the problem is the time the frames were rendered at, so what time in the game they show. the frames were finished almost at the same time and showing almost the same thing in the game.

so delaying one of the two so the frame times look smooth will only hide the problem, but it wont fix it. you would still see almost the same frame twice and only then see a new frame, again twice. so it will look like its stuttering, you see almost no movement between frames 1 and 2 and then to 3 theres a big difference, 3 and 4 are almost the same again and 5 is a big difference again...

Quote Originally Posted by DerekFSE View Post
From what saaya is saying though, there is no sync'ing? That just seems rediculous.
i dont know if there is or isnt, but the the frame calculation is def not perfectly in sync as ideally you want a crossfire system to shoot one frame from card 1 and then 1 frame from card2. and not have frame 1 and 2 come at almost the same time. then you are shooting 2x as many "bullets" as with 1 "gun", but your not producing a steady "cover fire" which is what crossfire is all about

Quote Originally Posted by tombman View Post
Hi, i'm the original author of the thread "die sli Lüge..." at 3dc forums and i'm happy that this problem is starting to get spread across the web.

ATI and Nvidia obviously don't want the world to know, because it will severly hurt the glamour of multi-gpu solutions which is the future of highend graphics!
The solution to this problem would be to enable some kind of intelligent frame limiter, which can easily be done within the driver, but will cost a small amount of average frames per second. And losing framerates will hurt benchmarks and therefore reputation.

Some games, that have a built-in framelimiter, will show perfectly even frametimes no matter how much gpus you use, so there IS a solution to this problem. In fact, a user @3dc forums already programmed a litte tool that can limit the framerate in all d3d9 applications, but then suddenly "disappeared" and never came back.

All this tool did was to delay the output of frames depending of previous frametimes. It wasn't intelligent, so you could only lock to a particular fps rate, e.g. 30fps or 40fps. Making it intelligent, so it could adapt to whatever framerate necessary in realtime, would have been no big deal, but as i said, he never came back to finish his work.

I hope, that with enough pressure from all of the "freaks" and "nerds" on the internet, ATI and Nvidia will have to come up with a solution, namely a small switch in the control panels of the drivers- for example they could call it: "syncronize/harmonize frametimes for SLI/CF" [Yes] [No]
interesting to see how many people noticed this but it never really became public

the tool your explaining doesnt solve the problem though, it will only have a cosmetic change in that the frame times will look fine, but as i explained above, the game will still stutter... the stuter would actually be even perceived worse cause you stretch the time between the two identical frames!