Anyone running Tri/Quad Crossfire in Vista...

[Banny]

Not good news for me with a 3870 on its way.

 

[HeX]

still worrying about the benchies hex?

ignore gpuz, its a bug anyway, your crossfire is working!

And you are still fooling yourself.

Crossfire isn't working, if it were my scores wouldn't be LOWER than a single X2.

My Crysis bench is identicle to running a single X2, my CoD4 fps is though the floor with crossfire supposidly enabled.

It quite clearly isn't doing what it is supposed to.

 

[kylew]

It could well be a bug, did you do a complete removal and re-installation of the drivers before adding the 3870?

 

[HeX]

It could well be a bug, did you do a complete removal and re-installation of the drivers before adding the 3870?

Yup.

First time I bunged the card in and fired up windows, it detected it, screen went blank then after 10mins when the HDD activity stopped I restarted.

The card was installed and Crossfire enabled by default, I fired up the benchies and noticed all was not as it should be.

So I uninstalled the drivers completely, restarted and let windows install default VGA drivers.

Restarted again and installed the 8.3's.

Restarted again and Crossfire was enabled by default in CCC, in game performance was exactly the same as when i'd just bunged the card in at the start.

I'm going to have annother play about with it tonnight, but I am rapidly running out of things to try.

 

[Banny]

still worrying about the benchies hex?

ignore gpuz, its a bug anyway, your crossfire is working!

its no way working with that performance.
when its working you will know about it.
we know yours is fine with your 45fps Crysis bench so you need not worry.

 

[Magnum_Force]

I'm begining to think crossfiring the x2 to a card in the 4x slot is somehow holding it back

The 4 x slot will bottleneck the card. Perhaps there are latency issues with the P35 chipset using the 4x slot for crossfire??.

 

[w3bbo]

The 4 x slot will bottleneck the card. Perhaps there are latency issues with the P35 chipset using the 4x slot for crossfire??.

Could be but an extra card running at 4x will be better than no extra card at all surely? I don't think it will help much with fps but with AA and higher res the extra memory should come in handy.

I am in a similar predicament but I am using a p35 blitz with the crosslinx chip (8x8 as opposed to 16x4) and I am unsure how the drop to 8x will effect the 3870x2 if I add another 3870. As the blitz is a rare board I am finding it difficult finding any results showing the benifits of doing so.

 

[HeX]

Could be but an extra card running at 4x will be better than no extra card at all surely? I don't think it will help much with fps but with AA and higher res the extra memory should come in handy.

I am in a similar predicament but I am using a p35 blitz with the crosslinx chip (8x8 as opposed to 16x4) and I am unsure how the drop to 8x will effect the 3870x2 if I add another 3870. As the blitz is a rare board I am finding it difficult finding any results showing the benifits of doing so.

My thoughts exactly, I knew the 4x slot would limit the 3rd cards performance, but it should still improve speed overall. It didn't in the slightest, and as i've said it actually reduces game fps and makes them look 'jerky' even when FPS should still be high enough for smooth gameplay.

Something is obviously not working as it should with Tri-Fire on the P35.

Anyway, i've sold the card now, I can 'live' with 'just' an X2 for now

Was a nice experiment, nothing ventured nothing gained as they say.

As for the Blitz, I don't think you'd be able to do the Tri-Fire route, if you did and the X2 dropped to 8x you'd be effectivly running 2 x GPU's at 4x and one at 8x... which is worse than a normal P35 with 2 x GPU's at 8x and one at 4x.

Deffo not worth doing.

 

[w3bbo]

So does each GPU on the 3870x2 use 8 lanes each? I thought the idea behind the onboard PCIe 1.1 chip was to make both gpu's act together as one?

 

[Mud]

For the record HeX, I'm on 2 3870X2s now and my control centre looks like yours did. Installing games now.

 

[HeX]

So does each GPU on the 3870x2 use 8 lanes each? I thought the idea behind the onboard PCIe 1.1 chip was to make both gpu's act together as one?

AFAIK it's a spliter chip, splits the 16x into 2 x 8x.

For the record HeX, I'm on 2 3870X2s now and my control centre looks like yours did. Installing games now.

Doubt you'll have a problem on an X38 m8, all the CrossfireX reviews are done on that platform and none reported any bugs.

I'm guessing its just a P35 thing

 

[Grumpy]

This might be a completely noobish answer, if so ignore me as per normal, however, could it not be that the card in the 4x slot is causinga bottleneck as they are physically connected via a xfire bridge? Thus causing the x2 to 'throttle back' to maintain some sort of simbiotic environment?

 

[WJA96]

This might be a completely noobish answer, if so ignore me as per normal, however, could it not be that the card in the 4x slot is causinga bottleneck as they are physically connected via a xfire bridge? Thus causing the x2 to 'throttle back' to maintain some sort of simbiotic environment?

The drop in performance is something between 7% and 20%. It's purely down to the bandwidth on the port - the card on the slower port still runs at full speed internally.

 

[-iceblade^]

worth it to Xfire on a P35 board then?

 

[Banny]

worth it to Xfire on a P35 board then?

Doesn't seem like it. might be a low level driver isssue, that will be fixed eventually, but like Hex said to me by the time its fixed, most people will have moved on.
I am waiting for a card to arrive so I can test, but after reading this post I changed my P5K P35 to a P5E X38 as I didn't want the same problem.
Seeing as I have pretty much got my system upto where I want, I didn't want this bug holding me back.
I will too post results on tri-xfire in this post, so we can see if it is only a P35 bug.