View Full Version : GTX 280 3x SLI - 3 Teraflops and/or 3 terrible flops?

07-04-08, 06:23 PM
GTX 280 3x SLI - 3 Teraflops and/or 3 terrible flops?


I wasn’t that busy at work yesterday and wrote most of the text for this post then when suddenly this more interesting pricing from nVidia started to appear along with nVidia's stock tanking. I bring this up only to say that the price vs. performance debate and recent cost reductions have nothing to do with this thread and those issues are being discussed elsewhere so please go to those places and discuss those issues.

The point of this thread is to not only to discuss 3x SLI performance but stability and usability as well. This is VERY informal and I’m not doing any comparisons with other cards or 2x SLI, that's a job for the pros.

Test System

Vista Ultimate x64 SP1
INTEL Core 2 Quad QX9650 @ 3.83 GHz (11.5 x 333 – FSB 1333)
ASUS Striker II Extreme – BIOS 704 Beta
XFX Geforce GTX 280 Standard Clock x3 SLI – Forceware 177.41
Enermax EGX1000EWL Galaxy 1000W
4GB OCZ OCZ3P16004GK PC3-12800+
2x Samsung 20X DVD±RW LightScribe Double Layer DVD
HP w2408h 24" 1920x1200 LCD Primary/Gaming Monitor
LG L246WP-BN Flatron 24" 1920x1200 LCD Secondary Monitor

Yeah, I know, no 30” monitor. That said the games I have benchmarked here seem to scale pretty well when game settings are set to high levels even at 1920x1200. Average frame rates in Crysis didn’t really seem to increase much from informal observation with 2x SLI but I was able to apply 4xAA and even 8xAA where it just wasn’t as smooth with only two cards.

SLI & Overall Gaming Experience

This is my fourth SLI setup (2 7800 512 GTX, QUAD-SLI 7950 GX2, one 9800 GX2 which is SLI in one card). They all had obvious and glaring problems from crashing constantly to simply not working at all to chocking at higher settings. Not this setup. I’ve played each of these games near the beginning of each for around twenty minutes or so to kick the tires:

Half Life L2 (HL2)
Half Life L2 Episode 1 (HL2 E1)
Half Life L2 Episode 2 (HL2 E2)
Assassin’s Creed (AC)
TimeShift (TS)
Lost Planet (LP)
Gears of War (GoW)
Call Of Duty 4 (CoD4)
Unreal Tournament III (UT3)
Call of Juarez (CoJ)

No problems going in and out of one game to the next with Word, IE, HWMonitor and Excel open except I had to reboot the machine to get Gears of War to run without crashing to the desktop but once I did everything was fine. I’ve had that problem with GoW before on another non-SLI system so I'm confident the issue has nothing to do with SLI. I did notice a microstuttering issue in CoD4 and then turned on triple buffering in the nVidia Control Panel profile and the problem went away. That’s the only setting I touched other than in game settings. All of these games ran beautifully with 3x SLI enabled.

I’ve seen reviews that show HL2 E2 not scaling in 3x SLI which I assume is the case, but when the game is fully maxed out and you’re still getting an average of over 150 FPS, scaling at that point isn't very important.

Power, Heat and Noise

I don’t have a power meter so I don’t know what I’m pulling from the wall. Guru3D has done a review on 2x and 3x SLI and they reported their rig as pulling 700W or so which in the real world is pretty high. I do remember Anandtech stating in their launch article that they thought that you’d need at least a 1200W PSU and that ordinary house wiring might be problematic. That’s BS. I’m using the same PSU that Guru3D used and its not having any problems. A top end 1kW is plenty for 3x SLI unless you have a LOT of internal peripherals and then I’d think you’d still be fine. It’s not like you’re going to be watching BluRay movies and playing Crysis.

As far as heat is concerned it shouldn’t be much of a surprise that there’s a lot. I got my cards from top to bottom at about 90/85/90 after about an hour of Crysis. And of course with all that heat there are three not so quite fans running at a 100%. I don’t have a noise meter either but yes, it’s pretty loud but I remember those two 7800 512 GTX’s in SLI I had a few years back and they were louder. If you care about heat and noise you’ll have issues to deal with and may want to go with water cooling. I have a window air conditioner in my bedroom office to augment the central air so it masks the noise and cools while I’m gaming when its warm so that’s how I deal with it. I like a little white noise. To each his own.


I had two of these overclocked to 660/1420/1150 and they seemed solid. With three in a not so spacious of a case I dropped back down to standard clock speeds. I think I want to improve cooling before I worry about more performance from a system that doesn't need it for now.

Other Considerations

At 1920x1200 this setup very CPU bound, anywhere from 50% to 80% CPU utilization on the benchmarks where 25% or less was the norm for a single GPU. Just my informal observations looking at my G15 CPU utilization meter but it’s pretty obvious. You’ll actually NEED that overclocked CPU for this type of setup.

Performance Numbers

For more formal performance testing I tested Crysis, the GRID demo, Lost Planet Extreme Condition and Call of Juarez.


For Crysis I benchmarked playing “Assault Harbor” from the first through the second cut scenes three times and averaged it together.


Not a 100 FPS for sure, in fact to a lot of people 35FPS looks bad until you play the game. I don’t have any numbers to prove it now but playing this scene or any scene for that matter with only 2 GTX 280’s with any AA turned on in game was much more sluggish.


This is fun and beautiful driving game and I included it in this review because the ATI 4800 series seem to do much better in this title than the GTX 280/260 and I was curious to see what 3x SLI could do. This is with every setting at maximum including AA and the game is ultra smooth and beautiful.


Lost Planet

For this game I used the built in performance tester. I first started playing this game on a Athlon X2 4800+ QUAD-SLI 7950 GX2 setup under Windows XP at 1680x1050 and it was a real pig. Even a single GTX 280 can’t run this game well at the ALMOST maximum settings shown here. I had to take the AA down from C16XQ to C16X. C16XQ was practically unplayable due to stuttering and not the micro variety either.


Call of Juarez

I don’t see this game in a lot a reviews but it’s very demanding, not as bad as Crysis but it gives a GPU a workout. Though I am not doing comparisons to 2x SLI I did notice how well this game scaled going from 2 to 3 cards. The average FPS went up 20 FPS. Not too bad.


UT3 – GPU PhysX

A note on the performance on UT3 and GPU based PhysX. Boy it seems slow. I didn’t bench it but from observation in playing the PhysX Lighthouse level with bots seemed to average only about 35FPS. That just doesn’t seem right as a single GTX 280 can easily handle this game sans PhysX. I need to look into this some more before I know what’s going on.


So there you have it. I may go back and try these benchmarks out with two cards but my main concerns here were Crysis performance and stability and usability issues. Stuff just worked with the exception of CoD4 needing triple buffering to clear up some microstuttering and the UT3 PhysX performance issue. Under load it’s pretty loud and generates a TON of heat. I may look at getting a bigger case as I don’t think that too much cooling would ever be a problem with three of these cards at full load.

Since we’re talking about at least $1500 as it stands today in GPU’s alone a 30” monitor is obviously what most people would want with this type of setup. However being able to turn just about every knob to max in everything, even Crysis with some decent AA, doesn’t make this setup useless at 1920x1200. You can still see noticeable performance gains though obviously not cost effective ones.

Happy Independence Day!

07-04-08, 08:09 PM
Good work! this is the first time i see a 100somethingFPS (in DX10 path) in Lost Planet :p

07-04-08, 09:49 PM
hot dam, you played crysis at those settings and had it still be playable.
and dont worry about the temps, the stock cooling is very capable, i believe they were designed so that they still perform well even while stacked right next to each other.

07-04-08, 09:59 PM
Yeah, I might be a little paranoid about the heat but its just so much that it makes me worry a little but but so far I've not seen any problems, just glad I have a window AC unit!:)

07-05-08, 01:54 AM

07-05-08, 02:04 AM
I know you said it but you should get a 30" monitor. Rigs like that deserve the best hardware to go with them.