• Welcome to Overclockers Forums! Join us to reply in threads, receive reduced ads, and to customize your site experience!

Crossfire bridges...do I need to use 2?

Overclockers is supported by our readers. When you click a link to make a purchase, we may earn a commission. Learn More.

attack

Member
Joined
May 23, 2002
I currently only use 1, GPU-Z says I'm not running Xfire, but ATI control panel says I am and when I run games I definitely see the increase in frames using FRAPS. Will I get even more performance if I use both? (only reason I don't is I use a large heatsink designed for passive cooling...which I've strapped fans onto of course...but I'd need to cut part of the heatsink to put on the second adapter.
 
Yes, you should have both bridges on. Don't worry about what GPUz says, if you have crossfire selected in CCC then its active. You can always tell by running a benchmark, like 3dmark06. Run it checked and unchecked and you will see a difference. GPUz doesnt show crossfire enabled right for 3800 series, at least for me it doesnt and I have seen many others saying the same thing.
 
You only need one to enable crossfire, but here's another deal: Running two bridges may cause texture "flashing" on certain games. I noticed texture flashing on Crysis with DX10 at max, but removing the second bridge fixed this issue entirely.

Cliff notes: two shouldn't matter, but sometimes it does -- and for the worse. Use one.
 
You only need one to enable crossfire, but here's another deal: Running two bridges may cause texture "flashing" on certain games. I noticed texture flashing on Crysis with DX10 at max, but removing the second bridge fixed this issue entirely.

Cliff notes: two shouldn't matter, but sometimes it does -- and for the worse. Use one.

hmmm, interesting. Im about to put a xfire rig together, thanks for the heads up.
 
I currently only use 1, GPU-Z says I'm not running Xfire, but ATI control panel says I am and when I run games I definitely see the increase in frames using FRAPS. Will I get even more performance if I use both? (only reason I don't is I use a large heatsink designed for passive cooling...which I've strapped fans onto of course...but I'd need to cut part of the heatsink to put on the second adapter.

The latest GPU-Z is supposed to correctly display crossfire status, but I haven't used it.

You only need 2 bridge if you run very high resolution modes (> 25xx by 25xx)
 
hey ajrettke..i see you have the same mobo and cpu as me...kinda off topic but i think you could prolly get 400x8 on that cpu....thats wat i have mine @ at 1.4125v....and i can also benchmark @ 3.6 ghz 400x9 @ 1.55v....but thats too high voltage for me to run all day...i get your o/c pretty much @ stock voltage...i really love this mobo cpu combo...and i think you would too....i can try to help you out with the bios settings if you would like...if you use xfire (the game messenger) my id is 187lordinfamous....well gl =()
 
I think I could as well but the limiting factor for me is heat I believe. I want to get a HSF, but I'm waiting till I get back to the states where I'm gonna move back to WCing. I might give 400x7 a whirl though to test FSB...then maybe 400x7.5 (I think I can do 7.5.....can't remember)
 
Your'e Da Man!

You only need one to enable crossfire, but here's another deal: Running two bridges may cause texture "flashing" on certain games. I noticed texture flashing on Crysis with DX10 at max, but removing the second bridge fixed this issue entirely.

Cliff notes: two shouldn't matter, but sometimes it does -- and for the worse. Use one.

"Texture flashing" I couldn't find a better word,, removing one bridge now....
 
What would you say to this? Found it on another board as I just bought two cards and they didn't ship with bridges so I'm using one from another HD 3870 I have as a single. The poster has an ASUS but my Gigabyte is 16x & 16x on both lanes.

No i need one as i already have one which came with the Asus card but there are two connection tabs on both cards by using only one connector it becomes PCI-e 8x crossfire so i need one more to make it run in PCI-e 16X crossfire mode here i'll explain better


the interconnects provide one 16 lane bus path which equate to 8 lanes transmit and 8 lanes receive
so by using two interconnectors you get a full 16 lane bus going both ways 16 lanes transmit and 16 lanes receive
 
1 bridge if you are running anything at 1680x1050 or lower, above that 2.

That at least is my understanding. I've seen and experienced this "texture flashing" and it cleared up after removing the 2nd bridge. I think newer CF is a little buggy compared to SLi.

And about the 16x-16x lanes. What mobo's are running a true 16x-16x? At the most i've seen 8x-8x. And that's on the new Biostar I45.
 
My understanding is my board does 16x by 16x which was one of the things that caught my eye.

Anyone have a bridge they would like to sell?

From the Egg spec sheet.

Expansion Slots
PCI Express x16 2 x PCI Express x16 (The PCIE_16_1 slot supports x16; the PCIE_16_2 supports x16.)
PCI Express x1 3
PCI Slots 2


From Gigabytes site

Expansion Slots

1. 2 x PCI Express 2.0 x16 slots
2. 3 x PCI Express x1 slots
3. 2 x PCI slots

and

GA-EX38-DS4
Help
Intel® X38 + ICH9R Chipset

1. Supports Intel® Core™ 2 multi-core and 45nm processors.
2. 1600 MHz FSB (Front Side Bus) support.
3. DDR2 1200 memory with Intel® ECC technology featuring faster speeds and higher data bandwidth
4. Revolution energy saving design with DES technology.
5. High quality CPU power module with Ferrite Core Chokes, Lower RDS (on) MOSFETs and Lower ESR Solid Capacitors.
6. Quad-Triple Phase Power Design for ultimate system stability.
7. Supports ATI CrossFireX™ with Dual PCI-E 2.0 x16 graphics for extreme gaming performance.
8. Integrated Dual LAN with Teaming function
9. Features SATA 3Gb/s with eSATA 2 interface.
10. ALC889A with DTS Connect enables high quality Full Rate Lossless Audio and support for both Blu-ray and HD DVD.


So I'm thinking I would like a second bridge. I put some OC on these and it stuttered a bit in 3dmark and my score wasn't as good when I had the same model in xfire yesterday.
 
Last edited:
I think that's the whole point of X38/X48, true dual x16 PCIe slots. What's this about crossfire bridges though? I thought you didn't need to physically link the cards anymore..??
 
I think that's the whole point of X38/X48, true dual x16 PCIe slots. What's this about crossfire bridges though? I thought you didn't need to physically link the cards anymore..??

that would be the first i've heard...im pretty sure you have to use 1 crossfire bridge on the x38/x48 as well as the p35's etc...but you only need to use one crossfire bridge...2 of them can cause system instability..
 
We'll see as I'm waiting on a new bridge. My scores went down using the Visiontek Revision 2 cards so unsure if its just them or now only having one bridge.

Hopefully in the next few days I get that second bridge and we'll get the benchmarks going.
 
2 seems to work for me

System configuration: Asus Rampage II Extreme with Intel core i7920 and 2 Asus EAH4870 512Mb Matrix cards. I seem to get a little fuzziness when running at 1680x1050 on my apple cinema display with one bridge. Once I changed this, I noticed smoother graphics and bettering color rendering at high frame rates. Hope this helps everyone.........
 
I've always ran with 2 bridges typically. I ran at 1920x1200 and never had an issue between 1 and 2 bridges.
 
Back