3-Way CrossfireX - Failed!

[Jayce85]

Hi,

I have tried two different Crossfire setups, using the same rig, but both of them performed so badly I started a thread on the AMD Game Forum - then someone locked my thread!?
http://forums.amd.com/game/messageview.cfm?catid=262&threadid=139433&enterthread=y

I would really appreciate a bit of feedback from anyone else who has tried 3-way crossfire - setups such as HD5970 + HD5870 don't count, neither do HD4870x2 + HD4870, as they are technically 2-way setups.

I'm talking 3 GPUs, 3 PCBs and 3 PCIe slots.

My test rig was a Foxconn ELA P45 (3 PCIe @ x8 speeds), I used 4GB RAM @ 1000MHz and a E8400 @ 3.8GHz. (900W PSU)
The cards I used were;
3x HD3870s (GDDR4)
3x HD4890s

Both setups destroyed 3DMark06 & Vantage, both sucked when it game to games.

What I found was 2-way Xfire worked great, but when I enabled the 3rd card in either setup, the frame rate became crazy erratic - with a max frame rate higher than 2-way, but the min dropped to lower than a single card!?
Averaging at no better than a single card.

I found an old Custom PC mag in which they compared 3 and 4 way Xfire v SLI, and my results with the HD3870s were identical to the magazines own results. With anything more than 2-way becoming a hinderance not a help.

2-way Crossfire seems to either work or not, it never gets WORSE than a single card.
So I've tested the best HD3000 and HD4000 series cards, which should have the better drivers - being well seasoned cards.

I know that it may be game specific but I hardly see the benefit of including a 3rd card that I am rarely going to use.

Anyone found a 3-way setup that works? Is it the ATI drivers or the games?

I'm guessing that it's the games - and not me...

 

[Jayce85]

It IS an ITZ series - but no it's not set to Turbo. I've heard of these things blowing up, so I'm not likely to switch it either.

For the HD3870 setup I originally used a 650W PSU, but thought that it may need more power, so i switched it for the Tagan, got a few hundred marks extra in 3Dmark06 - but still no fix for the game-frame issue...

 

[Jayce85]

I understand that when new technology is introduced it's in beta stages and it will take time before it becomes a reality, such as 6 core CPUs, DX11 aren't quite there yet.

It was a while before 2-way xfire got good - GTA IV only recently added Xfire support for instance. But I'm thinking 3 and 4 way is years away, perhaps never...

 

[Jayce85]

I've tried it at 1920x1200 as it's the max my monitor goes, but as i've said, my results were the same as Custom PCs Xfire/SLI review...

Like anyone running 3x HD3870 is going to have a 2560x1600 display (tho Custom PC did, but they don't count)

 

[Jayce85]

@ gareth170
Thanks - will give it a go using Turbo with my HD4890s.

As for some of the comments... i stated the motherboard I use is the Foxconn ELA - 3-way Xfire runs at x8 x8 x8.

I have to say I'm hardly unimpressed when I run 2 HD4890s together, my other system is a ASUS Deluxe P45 running a 12MB Cache Q9550 @ 3.6GHz - if thats what you call a bottleneck how can a x48 chipset be any better, using 8MB Cache CPUs?

Am on the verge of getting a P5Q3 for my Q9550 and using DDR3 ~2000MHz.

But even at the moment I'd say that my Xfire HD4890s & Q9550 are better than a HD5870 & i5 750.

 

[Jayce85]

Any proof of 3-way Xfire?

the 5000 series cards tested on P55 works just fine.

Are you talking about 2 or 3-way Crossfire? As 2-way HD4890s on P45 are great!

3-way is what sucks.

Do you have a link or anything showing a 3-way HD5000 series in Crossfire on a P55 chipset?
And as for performance i'm not talking about 3D benchmarks or Driving games, i'm talking across-the-board high-flying, 3 discreet GFX PCBs running smoothly in games.

All i can find is 2-way HD5850s or Hd5870s, i've even seen poor results of 2-way HD5770s (the apparent replacement card for the HD4890).

Some guy at AMD Forum claimed that HD5970 and HD5870 worked great, but the PC only sees that as 2-way Xfire. Has to be 3 GPUs on seperate PCBs.

 

[Jayce85]

@Freddie1980

Thanks! That was a real good review on tweaktown, thing is I can't seem to find a x38 or x48 mobo ANYWHERE!?

Scrap that - just found the exact board (Gigabyte x48 D6Q) on eBay. Let's see how it compares to my P5Q Deluxe...

Thanks, will post again once I've got it all setup!

Edit - Actually, before i go ahead with it all, I've seen a review of a x38 DDR3 board performing better than a x48 DDR2. I have a P45 DDR3 (ASUS P5Q3) on the way, would the P5Q3 with DDR3 be better than the x48 DDR2?

 

[Jayce85]

I've just had a ASUS P5Q3 (Intel P45 & DDR3) arrive, and a Foxconn Blackops (Intel x48 & DDR3) is on the way!
I'm going to use a Q6600 (Overclocked) with 1600MHz Corsair Dominator RAM for a 'CrossfireX Showdown' - 2 indentical systems of dual HD4890s only the chipset will differ (P45 v x48).
The Blackops also supports 3-way Xfire, so I can compare it to my Foxconn ELA (P45) results.

 

[Jayce85]

I for one never had any major issues with 3 5870's or 2 5970's. For some reason people just assume 3 way and 4 way is no use, usually those that have not tried it. Just because trifire and quadfire may have had issues in the past, doesn't mean it's always going to be the case.

I still don't think 2x dual GPU cards (HD5970 or HD4870x2) count as 'Quad-fire'.
As the system only recognises 2 cards. And games that previously didn't support Crossfire (GTA IV) still made use of both GPUs on a single card.
The reason you're not going to experience 'issues' with 3x HD5870s is because a single HD5870 is good enough to run most games at max settings.
Only if you were to benchmark your frame rates in games and have a look at the scaling of 1, 2 & 3 cards would you be able to notice 'issues'.
Some people can't afford £300+ gfx cards, let alone 3 of them! That's why using 3x HD4890s or HD3870s is useful, because we are supposed to end up spending on £150 - £300 on 3 cards, which is supposed to give up improved performance, negating the NEED to spend £1000 on graphics cards.