In AU there was a recent auction. A SLI pair of GTX7800 512MB (The one with the nicer cooler) and it went for around $25 + postage

kithylin wrote:

nforce4max wrote:

I wouldn't bother with the 9800gx2 due to the low overall quality and thermals but the gtx295 is better built. The 2900xt to me is one of those cards that I still desire. I liked how that after a lot of work SLI would prove its worth but was never easy like it is now and scaling along with the driver bugs back in the day didn't help. A very good rig got closer to 90% gain (avg was as low as 60%) after the second card was added but less than half of that on the third.

I found out myself later on that the scaling problem was because the systems of the time (mostly dual core systems), I've used for example a pair of 7800 GT's in my 4.5 ghz i7 and tried it with benchmarks with SLI off and SLI on, and found on a fast system the gains were nearly +95% from the second card, even using very old driver versions from around when the cards were common. So the drivers were fine, and the hardware was fine. We just didn't have fast enough computers at the time to realize it.

I tried that with my overclocked 8800GTS-640MB cards. When I ran the cards in my Opteron 185 @ 3GHz, SLI increased (and sometimes decreased) game performance by -5% to +20%. 3DMark Vantage received a 60% gain. When I benched the video cards in my i7-4930k @ 4.3GHz, the performance pretty much doubled every time.

Although, I suspect that the Microsoft NF4-SLI driver that came with Windows 7 may have been holding the Opteron back. SLI scaling was definitely better under Windows XP, using NVIDIA NF4 drivers.

Standard Def Steve wrote:

kithylin wrote:

nforce4max wrote:

I wouldn't bother with the 9800gx2 due to the low overall quality and thermals but the gtx295 is better built. The 2900xt to me is one of those cards that I still desire. I liked how that after a lot of work SLI would prove its worth but was never easy like it is now and scaling along with the driver bugs back in the day didn't help. A very good rig got closer to 90% gain (avg was as low as 60%) after the second card was added but less than half of that on the third.

I found out myself later on that the scaling problem was because the systems of the time (mostly dual core systems), I've used for example a pair of 7800 GT's in my 4.5 ghz i7 and tried it with benchmarks with SLI off and SLI on, and found on a fast system the gains were nearly +95% from the second card, even using very old driver versions from around when the cards were common. So the drivers were fine, and the hardware was fine. We just didn't have fast enough computers at the time to realize it.

I tried that with my overclocked 8800GTS-640MB cards. When I ran the cards in my Opteron 185 @ 3GHz, SLI increased (and sometimes decreased) game performance by -5% to +20%. 3DMark Vantage received a 60% gain. When I benched the video cards in my i7-4930k @ 4.3GHz, the performance pretty much doubled every time.

Although, I suspect that the Microsoft NF4-SLI driver that came with Windows 7 may have been holding the Opteron back. SLI scaling was definitely better under Windows XP, using NVIDIA NF4 drivers.

When I was testing on my i7 with the 7800 GT's I was using XP-32 too. Dunno if it mattered.

nforce4max wrote:

I wouldn't bother with the 9800gx2 due to the low overall quality and thermals but the gtx295 is better built. The 2900xt to me is one of those cards that I still desire. I liked how that after a lot of work SLI would prove its worth but was never easy like it is now and scaling along with the driver bugs back in the day didn't help. A very good rig got closer to 90% gain (avg was as low as 60%) after the second card was added but less than half of that on the third.

I've yet to see a dual GPU board (At least a "reference design") that doesn't run hot, sadly. This isn't a defense of the 9800GX2 by any means; I know they're space heaters (had a friend who ran four of them in the same machine for GPU computing - the thing was seriously better at heating up his apartment than an actual space heater 🤣). Ideally what I'd want for 3+ GPUs would be an external chassis, and as far as I'm aware the only commercially released example of that is the nVidia Quadro Plex, which appears to be on the way out with the release of Kepler based parts. Not to mention they're pretty expensive/rare boxes that are probably super-duper loud.

As far as 3/4-way scaling - from every demonstration, system, etc that I've yet seen it has less to do about offering higher frame-rates and more to do with making IQ enhancements (like AA) cheaper, and stabilizing the frame-rates. For example I remember benchmarks from a few years ago showing 1 through 4-way HD 4870 configurations, and the 3-4 way solutions rarely offered much more measured performance than 2-way CrossFire. HOWEVER, the 4-way solution could enable 32x AA with a minimal (usually negligible) performance hit, while doing the same on the 2-way setup usually meant unplayable frame-rates unless compromises were made (like lowering the resolution).

Tom's has also demonstrated that 3-way (or higher) will not demonstrate the micro-stutter phenomenon anywhere near as bad as dual GPU solutions, and the resulting frame-rates are much more stable (when looking at FPS values for dual GPU setups, be it a single card with two GPUs or two cards together, it should always be taken with a big grain of salt unless frame-time analysis is also provided - the micro-stutter phenomenon is to blame).

Another thing to consider is that if the game started out as a CPU bound title (or if the graphics cards are individually bound by the CPU), it will stay a CPU bound title (or the cards will remain CPU bound), and adding more GPUs won't do a whole lot for performance (I would theorize that it should still make AA cheaper, but can't confirm that).

When I had a 3-way GPU system (for one winter; it just made too much heat to run it year-round) it pretty much lived up to the above - I didn't see overall higher frame-rates in a lot of applications (compared to 2-way), but things looked/felt generally smoother (ignoring games that became unstable due to the configuration), and AA was certainly cheaper - I think 16x was the lowest I ever had to "settle" for, and most things would run with 24x or 32x quite happily. With two GPUs, 24x usually meant slowing things down to a grinding halt, and 16x was usually top of the mark.

Here's an article from S3 Graphics that explains their multi-GPU setup (with pictures and examples), and indirectly provides a pretty good summary of modern multi-GPU setups overall: http://www.s3graphics.com/uploads/download/wh … MultiChrome.pdf

obobskivich wrote:

subhuman@xgtx wrote:

Maybe one day I would like to get a 3-way Sli 8800 Ultra setup just for kicks.

I've thought of this too, either that or a pair of 9800GX2, but the power/heat and lack of a board that supports it (at least currently) is what keeps me away. 😵

Reportedly the higher-end Tri/Quad SLI setups will enable some pretty ridiculous AA levels (I've variably read between 32x and 128x; I know that 3- and 4-way CrossFire enables 32x, which looks pretty slick for older games).

I could force 128x/256x Antialiasing with my previous GTX680 4-way sli setup via Nvinspector heh; granted the 2 gigs of vram didn't cut it for anything too demanding but at least I could use those options when playing Daytona USA 2 Power ed. emulated on Supermodel3. The image quality was really great and would rival(if not better)that of 4x Full scene AA due to the lack of blur that the latter gives.

SSAA is what you really want right?

Mau1wurf1977 wrote:

SSAA is what you really want right?

OGSSAA only doesn't look as good. 4x + 4x MSAA is a good option too

subhuman@xgtx wrote:

Mau1wurf1977 wrote:

SSAA is what you really want right?

OGSSAA only doesn't look as good. 4x + 4x MSAA is a good option too

Found an old post of mine about this:

http://forums.overclockers.com.au/showthread.php?t=1005864

I admit I'm not up to date with the latest modes and utilities, but I do remember playing the first Bioshock with 2x SSAA and OMG the image was so beautiful. It was so calm, no shimmering, and everything looked consistent.

Mau1wurf1977 wrote:

Found an old post of mine about this: […]
Show full quote

subhuman@xgtx wrote:

Mau1wurf1977 wrote:

SSAA is what you really want right?

OGSSAA only doesn't look as good. 4x + 4x MSAA is a good option too

Found an old post of mine about this:

http://forums.overclockers.com.au/showthread.php?t=1005864

I admit I'm not up to date with the latest modes and utilities, but I do remember playing the first Bioshock with 2x SSAA and OMG the image was so beautiful. It was so calm, no shimmering, and everything looked consistent.

Indeed, it does help a lot to image quality. I am using the same method as you (nvidia control panel; 3840x2160). Maybe I'm just too exquisite but I'd love to see 8xFSAA running at 30 fps one day; I tried Serious Sam 3 BFE with a single 780ti at the already downsampled resolution + ingame forced 4xSSAA and despite running horrible, the thing looked wonderful. If only Nvidia cards had Rotated grid FSAA like 3dfx did...

Forgot my Tyan boards were Nvidia chipsets so no crossfire for my 4850's, bummer. What MB's do you guys recommend for an AM2/AM2+ crossfire system?

Unknown_K wrote:

Forgot my Tyan boards were Nvidia chipsets so no crossfire for my 4850's, bummer. What MB's do you guys recommend for an AM2/AM2+ crossfire system?

You can force sli on non nvidia chipsets but getting crossfire is another story and a can of worms. You could look into 690/790x boards but anything AM2 that is good isn't easy or cheap to come by but you might get lucky. Cringes at the thought of the expense of DDR2 1066 8gb kit.

Don't forget when building CF/SLi rigs that early Crossfire setups required one card to be a special "master" card. You couldn't just use any two cards of the same type like with nVidia.