Sli vs Xfire

[Snipe343]

is there any differance than ones with ATI and the others Nvidia(i think)

 

[demonbrawn]

That's the obvious. There's actually a bit of difference from the architecture to the way that they cards are connected. NVidia has used bridges for a long time, whereas ATi used to use these awkward dongles. Nowadays, they use bridges, too, but I think they use 2 bridges to NVidia's 1. There are plenty of other things you could talk about really...

 

[Snipe343]

witch is better then?

 

[a111087]

ATi has more performance gain, but that could have changed after new drivers and WinXP patches

 

[yogurt_21]

for the most part xfire has more perforrmance gain for the second card whereas sli is alot more stable and reliable.

 

[a111087]

hmmm.... stable? i don't know about that, never had SLI or Crossfire, I'm just glad my video card work

 

[sneekypeet]

I dont know where ya'll get your figures for performance,but here's somethin to ponder!!!!!! My 7600GT by itself does 7600pts on 3D05 @ 3.0Ghz with my Opty. Now when I add the second card for SLI at the same CPU speed I get 13,599 in 3D05. So you guys are telling this kid that Xfire is better in performance gain, So ATI offers a better gain than that?

 

[R-T-B]

I got a similar gain to that with my X1950 crossfire setup, yes. The exact numbers escape me at the moment, but it was pretty nice. Mind you, canned benchmarks are bad for measuring real world crossfire/SLI performance. Some actual games actually loose performance with 2 GPU's on both sides.

Right now, I'd say they are about effectively the same. SLI offers more driver control and the ability to make custom profiles. Crossfire hides all that from you and figures it out for you, and also offers a Super AA and supertiling mode (though supertiling doesn't offer much performance gain, just compatability with pretty much all games).

As you can see, the differences are actually quite small in practice. It really comes down to the cards more than the method any day of the week, so I'd start worrying about that and forget about which is "better," they are so close at this point it's hard to reccomend one over the other. It's the cards that really matter!

 

[Paradox]

I dont know where ya'll get your figures for performance,but here's somethin to ponder!!!!!! My 7600GT by itself does 7600pts on 3D05 @ 3.0Ghz with my Opty. Now when I add the second card for SLI at the same CPU speed I get 13,599 in 3D05. So you guys are telling this kid that Xfire is better in performance gain, So ATI offers a better gain than that?

05' is very raw performance oriented, lack of SM3 makes it fail for benchmarking new cards as does 06' with DX10 cards.

My 7600GT single got 3500~ and with SLi it was 5200~ WHEN they would actually stay in SLi... with my X1900GT+X1950XT (Yeah, two cards, different cores and CF interface!) and it got my score from 5900 to 7500

for the most part xfire has more perforrmance gain for the second card whereas sli is alot more stable and reliable.

Sli is anything but stable or reliable, half the time it never worked for me. Last stable nvidia drivers were the 64.XX's That's why I have a ATi now

 

[sneekypeet]

ok if we go with 06 I'm runnin 6872 in SLI...a huge boost from your own objective score of 3500!

 

[Paradox]

3500 was with a single stock card, and 5200 was with two stock 7600GT's. I'm talking stock speeds, not overclocked.

With my 7600GT overclocked at 820/1500 it got 5300 in a single card config.

 

[sneekypeet]

my bad as my cards run 650/800 stock..XFX flavor!

 

[Paradox]

my XFX was something like that only I think it was 500~/1400

 

[tkpenalty]

Whats the point of this thread =_=

 

[BarnyMiler]

I think the point is there really isn't any hard evidence supporting one technology over the other (SLI vs. Crossfire).

FWIW, you should really only expect a 40% increase in benchmark scores or FPS in most games when adding a second GPU. In some extreme cases you can see more, and in some other cases (where your CPU is your limiting factor) you might see way less. But a well-balanced system should see a 40% bump or so.

But it really comes down to personal preference in terms of which 'brand' you trust and support. I'm an NVIDIA convert after owning several ATI cards in the past that fell apart and/or died on me. I've switched to NVIDIA (and run SLI a few times) and haven't looked back since. Plus I'm in the Intel camp, which makes it easier to stick with NVIDIA.

 

[R-T-B]

I think the point is there really isn't any hard evidence supporting one technology over the other (SLI vs. Crossfire).

That's the truth. The only thing we can really go by is driver features, in which I actually have to give SLI the heads up for driver profiles. I'd much prefer that to this rediculess "you can't touch anything" stuff AMD has going on, even if they do have more rendering modes.

 

[AsGStorm]

it makes sense when you use SLI/crossfire for the cards to be the same right?

 

[R-T-B]

it makes sense when you use SLI/crossfire for the cards to be the same right?

It's probably best, yes. Crossfire doesn't require it (not sure about SLI), but you should ideally get cards of equivalent performance, maybe same brand if possible.

 

[Widjaja]

SLi 16X + 16X or 8x + 8x depending on the motherboard.

Crossfire 16X + 4X

3Dmark 06
Single HD2900XT 10888 marks
HD2900XT's in Crossfire 13917 marks.
599aus dollars or 1198aus dollars.

Single 8800GTS 320mb 10177 marks
320mb 8800GTS's in SLi 13619 marks
499aus dollars or 998aus dollars

It's just up to you whether you think it's worth the extra 3000 frames.

 

[niko084]

SLi 16X + 16X or 8x + 8x depending on the motherboard.

Crossfire 16X + 4X

3Dmark 06
Single HD2900XT 10888 marks
HD2900XT's in Crossfire 13917 marks.
599aus dollars or 1198aus dollars.

Single 8800GTS 320mb 10177 marks
320mb 8800GTS's in SLi 13619 marks
499aus dollars or 998aus dollars

It's just up to you whether you think it's worth the extra 3000 frames.

Are you sure Xfire runs in 16x + 4x? That doesn't make a whole lot of sense considering it keeps right up with SLI.... I mean thats true the simple way the cards communicate would have to be ridiculously more efficient.

 

[Widjaja]

Won't be a moment.
I'll look for a link on Crossfire setup having this sort of bandwidth config.
It was in one of my brother's mags.

And yeah it doesn't make a whole lot of sense to me either.

 

[insider]

CF is 8x + 8x

 

[newtekie1]

05' is very raw performance oriented, lack of SM3 makes it fail for benchmarking new cards as does 06' with DX10 cards.

My 7600GT single got 3500~ and with SLi it was 5200~ WHEN they would actually stay in SLi... with my X1900GT+X1950XT (Yeah, two cards, different cores and CF interface!) and it got my score from 5900 to 7500



Sli is anything but stable or reliable, half the time it never worked for me. Last stable nvidia drivers were the 64.XX's That's why I have a ATi now

I really have to dispute your numbers, if Crossfire with two x1950 series cards is only giving your 7500 then I would avoid crossfire at all costs. My two 7600GTs are getting 7400, so your two high end ATi cards are only getting you 100 more points in crossfire.

My single 7600GT gets 4200, in sli they get 7400. That is just over a 76% performance increase in 3dMark06. My 7900GT gets 5970, in sli they get 10250. That is just under a 71% increase in performance.

Using your Crossfire numbers you are getting just over a 27% increase!
Using your SLI numbers you are getting just over a 48% increase with SLI!

So even using your numbers I don't see why you are saying SLI is worse.

As for the stability of each, I can't comment on Crossfire as I have never used it(frankly the motherboards never interested me, they are too expensive on the Intel side, and the chipsets are terrible on the AMD side).

However, I can comment on SLI. When the 90 series drivers came out SLI was flakey at best. However, that was fixed rather quickly. By the 94 series drivers they SLI issues were fixed and I didn't have a single problem enabling SLI. Now, I did have problems after that when I started using modified drivers from the 8800 series on my 7x00 series cards, but again those were modified drivers. Now that we are on the 162 series all the SLI problems have been fixed, even though I am still using the beta driver and haven't updated to the official release yet.

 

[yogurt_21]

e6600 at 3.6GHZ vs an stock opteron, cpu makes abig difference in 3dmark 06, and if you two were to compare scores, you'd find that it was you cpu that made the biggest difference.

 

[newtekie1]

e6600 at 3.6GHZ vs an stock opteron, cpu makes abig difference in 3dmark 06, and if you two were to compare scores, you'd find that it was you cpu that made the biggest difference.

I wasn't talking about comparing scores, I wasn't comparing scores with him. I was comparing how much of a benefit SLI was giving vs. Crossfire vs. single cards.