PCI-E link width running at x8 instead of x16

[creepo223]

I have an MSI MS-7390 motherboard and an EVGA Nvidia 9800 GTX+ videocard. When I check in CPU-Z and the nvidia system information, my PCI-E link width is only running at x8, not the x16 it's supposed to run at.

This motherboard is PCI-E 1.0 or perhaps 1.1, it's not 2.0, so I'm taking a huge bandwidth hit presumably. Can anyone help me figure this out? I've just spent about two hours reading every post on the internet about it and no one seems to have any info on how to fix this.

 

[Vette73]

I'm guessing the board thinks it is in SLI mode. Is there anything in the Bios to turn off the 2nd PCIe slot?

 

[Kenmitch]

Is your video card in the upper pci-e slot? Other than that have you tried reseating the card yet?

 

[creepo223]

I'm guessing the board thinks it is in SLI mode. Is there anything in the Bios to turn off the 2nd PCIe slot?

Not as far as I can tell. All I saw was spread spectrum control, which only has the option for "Triangular Down", which I assume gives my computer downs and turns the tower into a pyramid, so I'm not going to mess with that. No, honestly I tried that setting and it didn't fix anything.

The only other option I found was something about "auto disable pci something or other" which I tried as well and it accomplished nothing.

Is your video card in the upper pci-e slot? Other than that have you tried reseating the card yet?

It's in the upper slot, which according to my motherboard manual is the first pci-e x16 slot. I took it out, checked the 6 pin connector, then re-seated it, no change. Are you suggesting I put it in the second slot?

 

[Kenmitch]

It's in the upper slot, which according to my motherboard manual is the first pci-e x16 slot. I took it out, checked the 6 pin connector, then re-seated it, no change. Are you suggesting I put it in the second slot?

Was just checking to make sure you didn't put it in the lower slot. You could maybe try cleaning the contacts on the card with rubbing alcohol and a coffee filter, maybe blow out the upper slot with some compressed air. If that doesn't work then maybe try the other slot for kicks.

 

[creepo223]

Is it possible that my motherboard only has x8 pci-e slots? It's an SLI board but I've never really wanted to use it for SLI, I just wanted a single x16 slot.

 

[Kenmitch]

I downloaded your manual to take a look and it looks like it'll only do 8x upper and 4x lower as far as I can tell. Are you sure it's suppost to do 16x?

 

[fffblackmage]

This motherboard is PCI-E 1.0 or perhaps 1.1, it's not 2.0, so I'm taking a huge bandwidth hit presumably. Can anyone help me figure this out? I've just spent about two hours reading every post on the internet about it and no one seems to have any info on how to fix this.

I'm sorry I don't have any suggestions for fixing the problem, but it's not as serious as you think it is. It does half your available bandwidth, but does it matter? Nope, especially not with a 9800GTX+.

Someone did a benchmark comparing 6950s in crossfire in 16x/4x and 8x/8x modes and found very small differences in the results. I doubt 8x PCIe v1.1 will hurt your 9800GTX+'s potential.

http://forums.anandtech.com/showthread.php?t=2134562

 

[taltamir]

try contacting the mobo manufacturer's customer support