Question SLI GTX 970s running at reduced bandwith

[alexcameron26]

i have dual ASUS STRIX GTX 970s running in SLI, i have noticed that one card runs in X8 mode and the other in X1 mode even tho there is no other PCI deviced connected that would take lanes away from the GPUs, is there a way to get both cards to run in X8 mode? CPU is a i5-4690K and the board is a ASUS MAXIMUS HERO VII

 

[Eximo]

When are you measuring this? If not under load, it would make a lot of sense for the second card to throttle down to 1x. Considering how much less prevalent SLI is, what games or applications are you using to test?

 

[alexcameron26]

When are you measuring this? If not under load, it would make a lot of sense for the second card to throttle down to 1x. Considering how much less prevalent SLI is, what games or applications are you using to test?

im measuring this under load sorry should have mentioned that, and im running GTA V and Mass Effect Andromeda

 

[Eximo]

Maybe try the previous Nvidia driver, I know there were some CPU usage issues with the latest one, not sure if they have gotten around to fixing it. (I'm a few months behind myself, but I am not playing anything new at the moment)

Re-seat the cards perhaps. I have had really weird behavior from a sagging GPU that was solved simply by pulling it and re-inserting.

Maybe check the BIOS for anything out of the ordinary. Reset might work as well, or update if you aren't on the latest.

 

[alexcameron26]

Maybe try the previous Nvidia driver, I know there were some CPU usage issues with the latest one, not sure if they have gotten around to fixing it. (I'm a few months behind myself, but I am not playing anything new at the moment)

Re-seat the cards perhaps. I have had really weird behavior from a sagging GPU that was solved simply by pulling it and re-inserting.

Maybe check the BIOS for anything out of the ordinary. Reset might work as well, or update if you aren't on the latest.

checked everything you said , and checked BIOS settings and i just realized something odd, the top full X16 slot is running in X1 mode and the second slot is running in X8

so the main card is in X1 mode and the second card is in X8 mode

this cpu has 16 pcie lanes, im using 9 of them technically

 

[Eximo]

Maybe re-seat the CPU too, that does seem odd. Nothing else should be shared with the CPU lanes.

 

[DSzymborski]

i have dual ASUS STRIX GTX 970s running in SLI, i have noticed that one card runs in X8 mode and the other in X1 mode even tho there is no other PCI deviced connected that would take lanes away from the GPUs, is there a way to get both cards to run in X8 mode? CPU is a i5-4690K and the board is a ASUS MAXIMUS HERO VII

You say no other PCI device, but you didn't specify SATA. SATA0 and SATA1 are also shared with the second PCIE slot.

 

[alexcameron26]

You say no other PCI device, but you didn't specify SATA. SATA0 and SATA1 are also shared with the second PCIE slot.

so how would i rectify that, yes i have three SSDs and there using the top 3 SATA ports?

also its not the second PCIE slots thats being affected its the main top X16 slot thats running in X1 mode

 

[alexcameron26]

so update, i swapped the card around, and now the top slot is X8 and bottom is X1 so im now thinking maybe one of my cards is got an issue

 

[DSzymborski]

Do they each run at x16 when they're by themselves? You really want to isolate the problem.

 

[alexcameron26]

Do they each run at x16 when they're by themselves? You really want to isolate the problem.

Found the issue one card is stuck in X1 mode permanently so I guess I'll have to find a replacement or replace both with something newer in the meantime I'll just run it as the secondary card in the sli setup while I find the money to replace it or both cards

 

[DSzymborski]

Found the issue one card is stuck in X1 mode permanently so I guess I'll have to find a replacement or replace both with something newer in the meantime I'll just run it as the secondary card in the sli setup while I find the money to replace it or both cards

Well, don't replace both. SLI was always a stretch with this setup given the VRAM, and SLI/Crossfire driver support ended years ago. You'll likely be better off with one stronger card.

 

[alexcameron26]

Well, don't replace both. SLI was always a stretch with this setup given the VRAM, and SLI/Crossfire driver support ended years ago. You'll likely be better off with one stronger card.

i meant replace both with one newer card, maybe hunt down a 1080ti, i dont play games that require more power then that anyway