Crossfirex on the ga-h55-ud3h

hector_01

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Mar 2, 2008
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Hello all. I just recently purchased the h55 UD3H motherboard. I have my second hd5870 getting replaced at the moment and what i have noticed is that the 2 pcie slots for the video cards are much too far apart for any type of crossfire cable that i know of (10cm being the longest). There are 4 pci slots between the 2 graphics card ones and the box says it is crossfirex compatible so im really stumped as to why they would be so far apart. Does anyone know of a crossfire cable that is longer than 10cm????
 
Solution
Intel lists the chipset's pathways as PCIe 2.0 but 2.5 Gb/s, which is 1.0/1.1 speed. Evidently they added some compatibility without adding capability.

All the "H" chipsets have the same limitation when it comes to preventing CrossFire on the CPU's sixteen lanes.

Crashman

Polypheme
Former Staff
That other slot isn't meant to provide CrossFire.

Let me repeat, it's not for CrossFire. While it will work for CrossFire, it's only an x4 slot.

Worse than that, it's an x4 slot running at half speed. In other words, it's only 1/8 the bandwidth of the first slot.

That slot is there for your low-performance graphics expansion needs, such as when you're using additional monitors in an office. It might also work for adding a low-end Nvidia graphics card to be used as a PhysX processor.
 

hector_01

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Mar 2, 2008
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No offence but the fact that it says on the box and on the gigabyte site that its crossfirex compatible and it says when IN CROSSFIREX mode the first slot runs at 16x and the second runs at 4x whuch you did say but it just seems odd that it wouldnt be used for crossfire mode even though it says it is. Why would would it only run at 1/8th the speed i mean im only coming from a basic mathematical view but 4x would be 1/4 wouldnt it??? Anyway thanks very much for the reply and if it truly is the case that it isnt meant to be for crossfire then time to get a different motherboard lol.
 

hector_01

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Mar 2, 2008
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i was looking into it a bit further and when you say the 4x slot runs at 1/8th thats only when it is a pcie 1.0 slot but the 1156 chipset i thought were pcie 2.0 so that wouldnt be the case right??? i saw an article on the 16x 4x and its really only a 5% performance decrease generally over 16x 16x with the 1156 chipset. But im no expert thats for sure and this is just what i gathered from the net. Thanks again for the info crash
 

Crashman

Polypheme
Former Staff
Intel lists the chipset's pathways as PCIe 2.0 but 2.5 Gb/s, which is 1.0/1.1 speed. Evidently they added some compatibility without adding capability.

All the "H" chipsets have the same limitation when it comes to preventing CrossFire on the CPU's sixteen lanes.
 
Solution

hector_01

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Mar 2, 2008
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Thanks again crashman. They like to make things confusing when picking a motherboard but thats ok i can use it for a media centre pc. Cheers for the info