X-Bit Labs Does Quad SLI/Crossfire

[BFG10K]

They tested plenty of games and the results were inconsistent at best, swinging wildly according to the game in question.

Plus there's the issue of possible mouse lag and/or micro-stuttering even when the framerate is high, numerous driver problems on both sides, and both sides overheating as well.

There's no way I'd pay for something like this.

I think they summed it up well:

At this time, they are mostly an expensive toy for computer enthusiasts with unlimited budget who love playing with computer hardware, rather than stable and reliable elite gaming platform for everyday gaming fun.

http://www.xbitlabs.com/articl...y/geforce9800-gx2.html

 

[manimal]

micro stuttering made me give up on sli....

 

[thilanliyan]

What exactly is micro stuttering? Can you point me to a video of it? Does it affect Crossfire as well?

 

[Engineer]

Originally posted by: thilan29
What exactly is micro stuttering? Can you point me to a video of it? Does it affect Crossfire as well?

Small freezes within games. Very anoying. Try UT2004 on your 8800GT to see what micro stuttering is (almost guaranteed to see in on there from my own experience and what I've read).

 

[djnoob]

What I think is funny is that they are using the 174.53 drivers which don't support quad-sli. Maybe they should have waited until they got proper drivers before posting the review.

 

[aka1nas]

FWIW, I've only seen micro-stuttering occur on machines(SLI or single GPU) with inadequate power or with GPUs that were OC'ed too high and thus unstable. I've usually overspecced somewhat on the PSU for my own SLI setups , and I have not been able to experience the issue on those machines.

 

[Wreckage]

Originally posted by: BFG10K

Plus there's the issue of possible mouse lag and/or micro-stuttering even when the framerate is high, numerous driver problems on both sides, and both sides overheating as well.

You should just put this in your sig.

 

[CP5670]

Originally posted by: Engineer

Originally posted by: thilan29
What exactly is micro stuttering? Can you point me to a video of it? Does it affect Crossfire as well?

Small freezes within games. Very anoying. Try UT2004 on your 8800GT to see what micro stuttering is (almost guaranteed to see in on there from my own experience and what I've read).

That is actually a different problem and is caused by a bug with that specific engine in the Nvidia XP drivers. It apparently doesn't occur in Vista or on older Nvidia cards.

This article describes the issue. It seems to be a result of the AFR method that both SLI and Crossfire use for splitting the load between cards.

 

[angry hampster]

God I'd love to play Crysis with a GX2 at 19x12 on DX10 high with some anisotropic filtering and shaders on very high.


These guys have got to be having fun testing this stuff

 

[lopri]

Originally posted by: Engineer

Originally posted by: thilan29
What exactly is micro stuttering? Can you point me to a video of it? Does it affect Crossfire as well?

Small freezes within games. Very anoying. Try UT2004 on your 8800GT to see what micro stuttering is (almost guaranteed to see in on there from my own experience and what I've read).

I think that is a 'regular' stuttering. Micro-stutter is a lot more 'micro'. As a matter of fact, a lot of folks might not notice it. (like some people didn't see 'shimmering' untill pointed out) I wish I hadn't learned about it, in retrospect. Sometimes ignorance is bliss. (no pun intended)

 

[thilanliyan]

So both multi GPU solutions suffer from this? Is it noticeable? I WAS considering multi GPU for my next build but this might put me off.

 

[djnoob]

Did noone read what I wrote?

The drivers listed that they used were 174.53. These are not quad sli drivers. The drivers to enable quad sli will be released tomorrow.

http://www.fudzilla.com/index....=view&id=6435&Itemid=1

As soon as the drivers are made available I'll do some benches and post them here.

 

[n7]

Good grief what a mess.

On both sides, driver issues like no tomorrow, & this is with primarily mainstream games too.

The terrible minimum fps makes me want to cry.


The other day i ordered myself an HD 3780X2 to compare to my GTX for fun, & i fully expect to end up returning it due to issues...time will tell though.

 

[Sylvanas]

Results are all over the place, however I am very happy with my Crossfire setup- I haven't 'noticed' any micro stuttering so it must be quite subjective. Would be good to revisit this a year down the track with more mature drivers and see how it plays out.

 

[Engineer]

Originally posted by: CP5670

Originally posted by: Engineer

Originally posted by: thilan29
What exactly is micro stuttering? Can you point me to a video of it? Does it affect Crossfire as well?

Small freezes within games. Very anoying. Try UT2004 on your 8800GT to see what micro stuttering is (almost guaranteed to see in on there from my own experience and what I've read).

That is actually a different problem and is caused by a bug with that specific engine in the Nvidia XP drivers. It apparently doesn't occur in Vista or on older Nvidia cards.

This article describes the issue. It seems to be a result of the AFR method that both SLI and Crossfire use for splitting the load between cards.

Thanks for the clarifications on Micro-Stutter!

I considered the stutter "micro" because when I Yahoo'ed the problem, it was described "micro" on most of the sites that I read.

 

[BFG10K]

What exactly is micro stuttering?

It's basically irregular intervals between frames which leads to a hitching feeling even when the framerate is high.

Does it affect Crossfire as well?

It'll affect any multi-GPU setup that uses AFR style rendering, so yes.

 

[thilanliyan]

Originally posted by: Sylvanas
I haven't 'noticed' any micro stuttering so it must be quite subjective.

Hopefully it IS subjective. I'd really like to see it in the flesh but I don't wanna waste money just to see that.

Originally posted by: BFG10K

What exactly is micro stuttering?

It's basically irregular intervals between frames which leads to a hitching feeling even when the framerate is high.

In a single GPU do you not see this because the interval is the same but the time to render could be higher from frame to frame (ie. lower fps but same interval)?

 

[lopri]

Micro-stutter is very different from regular stutter. When 'regular' stutter occurs FPS actually drops momentarily but with micro-stutter there is no FPS drop whatsoever. Best way to see it is (ah.. my evil side) to look on the ground while running. In an opposite fashion of shimmering, it's more prominently showing in close distance (bottom half of the screen).