7970 Won't boot in PCI-E Gen 3 mode

[SneakyBushNinja]

Hello,

I have an HD 7970 DirectCUII card which was purchased today. I've installed it into my Sabertooth X79 motherboard (which currently had an HD 6800 series card working in it) and it failed to boot in PCI-E Gen 3 mode. I ended up having to put the 6800 back in to get into the BIOS and set to PCI-E Gen 2 mode. Upon doing that the card works as expected (Using the Asus driver, the current AMD provided driver produced strange artifacts).

I'm kind of at a loss as to how to get this card working in PCI-E Gen 3 mode. I even tried setting 2 of the x16 slots to gen 2 and just one slot to gen 3 with no luck.

Thank you in advance for any support.

[HiVizMan]

All you should do is reset your BIOS back to default and Gen3 will be back as per normal.

[SneakyBushNinja]

I'm not having any difficulty setting the slot to PCI-E gen 3, or even using it in that mode with a 6800 series card. It's when it's in PCI-E Gen 3 mode and there is a 7900 card in there (only gen 3 card I own or I'd try another) the system produces a beep code of one long and 3 short (if I recall correctly). I looked up the beep code and it just said that something is wrong with the video....

[Kipper]

Just a thought, are you using the latest driver, 12-3 I believe.

[SneakyBushNinja]

Just a thought, are you using the latest driver, 12-3 I believe.

I'm using the latest driver from support.asus.com, the latest driver from the AMD website produces hardcore artifacts in DX 9 and 10 games. However, this is very much pre-32bit mode where the driver would come into play, as it happens right at boot and prevents the POST from completing.

[stitch]

So it isn't POST-ing, it's beeping... Are you sure you're in the correct slot? Likely the very top PCIe 16x slot? If yes, it could be a BIOS issue, set it back to PCIe 2.0 and check to see if there is an updated BIOS for your motherboard for this issue.

[SneakyBushNinja]

So it isn't POST-ing, it's beeping... Are you sure you're in the correct slot? Likely the very top PCIe 16x slot? If yes, it could be a BIOS issue, set it back to PCIe 2.0 and check to see if there is an updated BIOS for your motherboard for this issue.

I have tried it in multiple slots with multiple settings. I'm just going to throw this out here... it IS a BIOS issue, I established this in my first post. I also established in my first post that by setting the slot' link speed to PCI-E Gen 2, it works, if I set it back to Gen 3, it doesn't post and provides the beep code.

I am using the Asus Sabertooth X79 board with BIOS revision 1009. I did however just notice there is now BIOS revision 1104 available on your site, so I will give that a try.

[SneakyBushNinja]

I have tried it in multiple slots with multiple settings. I'm just going to throw this out here... it IS a BIOS issue, I established this in my first post. I also established in my first post that by setting the slot' link speed to PCI-E Gen 2, it works, if I set it back to Gen 3, it doesn't post and provides the beep code.

I am using the Asus Sabertooth X79 board with BIOS revision 1009. I did however just notice there is now BIOS revision 1104 available on your site, so I will give that a try.

I have just finished flashing my BIOS and re-doing all of my settings. The card now appears to be working correctly at PCI-E Gen 3 settings.

Thank you for all of your help,

-Wes

[stitch]

As an old hand at system troubleshooting, checking to see if you have tested something specifically allows us to better understand how you've gone about things. Now that you've confirmed that clearly, yeah, it definitely does look like a BIOS issue is the source of your grief.

It also looks like they've had BIOS issues with PCIe 3.0 Support in general, so you may not be alone there.

Just a note, as far as I can tell, ASUS reps aren't plentiful so you're mostly going to deal with other end users for support when going through this forum.

[HiVizMan]

ASUS reps are most certainly not plentiful. I did not quite understand what it was you were asking originally.

And yes there have been a number of instances where Gen3 settings have not been kind to the HD7970 cards, or it could be the other way round I guess. The funny thing is that a card that will not work in one board will work in another, both the same make and model.

I am just very pleased that you have sorted your issue out and can now enjoy your system as you should.