four graphics cards on "ASUS Crosshair V Formula"- is it possible?

[m4rtin]

If one does not count in space restrictions, then is it possible to use four PCI-E graphics cards on "ASUS Crosshair V Formula"? If yes, then how many PCI-E lanes are dedicated to each PCI-E slot? According to official documentation only three PCI-E graphics cards are supported- first PCI-E slot gets 16 lanes, second and fourth one will get 8 lanes.

[DaemonCantor]

m4tin, on the Crosshair V only 3 cards are supported any thing more can't be done because of the lack of PCI-E Lanes in both Hardware and Software(BIOS). if you were able to get 4 in there one card would be stuck in a 1x setup because the other 3 would default to an 8x setup taking up all of the band width, this part is programed in the BIOS to do just that and a Video card as far as I know will not function without at least 4x so the card stuck in the 1x wouldn't work or the system would not post from a Hardware Error...I can see an argument for both possibilities.

[m4rtin]

DaemonCantor wrote:
Video card as far as I know will not function without at least 4x so the card stuck in the 1x wouldn't work or the system would not post from a Hardware Error

Graphics cards work with a single PCI-E lane as well. This is sometimes used in server motherboards where there is a x16 physical PCI-E connector with x1 lane for video card.

However, I tried to find a setup where "ASUS Crosshair V Formula" is used with four graphics cards and I did not find any information :rolleyes:

[DaemonCantor]

I would agree with you m4tin except I have never seen a video card that would plug into a 1x slot and as you pointed out a special circumstance where this set up could be possible but it doesn't exist because if the server board would have an Onboard GPU instead. I do understand that Servers have a very Underpowered GPU but it's because they don't normally have Monitors attached to them because they are administered remote. The other problem for a Server to have a x16 slot is that it's not for a Video card at all but instead it's used for cards like Fiber Chanel RAID's or Fiber-Optic Network Cards and such that also need a 16x Slot. Check out some High-End Server RAID Cards and you'll see.

As to the Crosshair V that's a totally different thing than a Server Board and because of that fact they are made Differently but since I've never pushed the fact Please try it and let us know what happens.

[m4rtin]

DaemonCantor, for example PCI-E x16 connector of Intel S3210SH motherboard operates in a way that if it detects a graphics card, it will switch to x1 lane mode. From the motherboard manual:

One PCI Express* x16 connector to be used as a x16 link from chipset (If a VGA adapter is inserted into this slot, the VGA card will only work at PCI Express* x1 speed; this is a chipset limitation.)

However, I'll try to find a single-slot AMD Radeon HD graphics card and try this out. At the moment I have PCI-E slots 1, 2 and 4 populated. Slot 3 requires single-slot card. To make matters worse, this graphics card has to support AMD Stream.

[theoneandonlymr]

ive had all four slots filled since day 1 with two 5800 in xfire plus hybrid PhysX card and a pciex ssd, the first three pciex are directly connected to the cpu Nb and will all run at x8 if all filled , the fourth is from the chipset and is stuck at x4 max but stays at x4 despite whats in the first 3 , the second pciex will drop to x1 only if gfx cards are in 1 and 3 and you use a non gfx pcie card in it ie an ssd. all of this is absolute and actually tested by me

so with four amd cards in (space allowing) the first three will run at x8 the fourth would be at x4, oh and a gfx card Will try and work at x1 in a x16 slot if only x1 bandwidth is swithed to it

[DaemonCantor]

Thank You theoneandonlymrk! Now that's is good info that I didn't know and I was basing what I had stated of of past experience and research. Also you have pointed out that the ATI/AMD Cards will run with PhysX On and that the Patch I spoke of in another thread does work. I thank you for that as well.

[theoneandonlymr]

no prob daemoncantor, im on win 8 with the latest 13.2 ati drivers and latest whql NVidia 310 I think ,used phsyx mod 1.05 and alls well , I have messed a lot with all four slots to get the best running system and found the above to be true ,mine are not optimal due to the ssd but hey ho you gota try these things.