Maximus V Formula - 1st PCIe 16x slot stuck at x4 link speed

[NLight95]

The first PCIe 16x slot in my Max V Formula is stuck at x4 link speed and despite re-flashing to several different earlier BIOSes (1309, 1408) and disabling C3 & C6 reporting, it doesn't change. I'm using a Sapphire 7970 OC. Moving it to the second 16x slot shows an x8 link speed, and the third at x4 (both of them are operating properly accordinfg to the manual). No other expansion cards are installed, just the 7970 alone.

I've owned my MVF since last July but only noticed this recently because I had no need to play around with the NB PCIe Configuration. It was after I saw the results in GPU-Z & CPU-Z, then confirming it in the BIOS itself (currently 1604) where the Link Speed is showing as x4.

Any help would be appreciated. Thanks!

This is what I've tried thus far:

1. Blow out PCIe X16 slot one with compressed air
2. Reseated 7970 (several times) and reinstalled 3570K
3. Reset to BIOS defaults
4. Flashed back to both 1408 and 1309 BIOSes but no change, so went back to 1604
5. Tried different Gen settings with no effect (it's not the problem anyway as PCIe 3.0 is working)
5. Tried my old HIS 4890--same results, link speed stuck at 4 (it's a Gen2 card with a 16x link)

CPU-Z


GPU-Z, 7970 at idle



GPU-Z, 7970 under load

[Chino]

What method were you using to do your BIOS reflashes?

[NLight95]

Chino wrote:
What method were you using to do your BIOS reflashes?

From the EZ Flash 2 Utility in the BIOS via USB flash drive. I always clear the CMOS and reset to defaults before flashing.

[NLight95]

This is what's showing in the BIOS under NB Configuration.

[NLight95]

duplicate post--delete me

[HiVizMan]

Could you please run a vantage benchmark with the 79xx series card fitted and post up your game test details here.

[NLight95]

HiVizMan wrote:
Could you please run a vantage benchmark with the 79xx series card fitted and post up your game test details here.

Sorry about the double post--I really don't know how it happened as I edited the original. Even though I could view the second image from my Photobucket account, it wouldn't allow me to reference it; so I uploaded the image again and updated the link. Hopefully this time it'll "stay."

Here are my Vantage results:

[HiVizMan]

Your card is performing as expected. You are not losing any performance at all. In fact your result would put you in the upper 160 results on HWBOT and better than some of the cards clocked at 1200MHz.

So I hope that puts your mind at rest.

[NLight95]

Keep in mind that this is NOT a standard 7970. I have a Sapphire 7970 OC w/Boost where the GPU clock is 1000 and VRAM is 1450.

I set the 7970's clocks to stock speeds (925/1375) and ran Vantage again.

[NemesisChild]

Have you tried reverting to an older bios, like 0804?
This is the bios that I've been running ever since I bought the MVF.
No problems whatsoever with 0804, rock solid stable as well.