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2080ti Gpu-z says running at pciex8?

malccy

malccy

malccy

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Torquay, Devon, UK
hi

am a little confused with m.2 drives with regard to pcie lanes for gfx card.

Have an Asus z370-prime motherboard with a 500gb m.2 at top of motherboard and a Sabrent m.2 drive at lower part of motherboard. I have read that the lower Sabrent drive stops the use of one of sata ports.

My 2080 is in the upper pciex16 slot on the motherboard.

Is the gfx card sharing lanes with the m.2 at top and if so why is the bottom one connected to the sata ports? Gpu-z reports the 2080 as only using pciex8.

Am quite confused - how do I run my 2080 in pciex16 and use both my drives?

I also have a problem, quite often win10 will be in an awful low res when boot up and initially nzxt see's no display device but after a min or so the screen will go black before screen returns and in native 2560x1440p res. Anything I can do to fix?

Many thanks for help, much appreciate.
 
It's motherboard /chipset dependent
I run 3 x M2 pcie~x4
And lose 2 sata ports
But graphics slot 1 still gets x16
Slot 2 wont
But it's x570 board
Really need to read your motherboard manual
But it sounds about right what you are getting
 
Nvidia cards show as using 1x when idle but goes up when you do the inbuilt render test in gpuz (the ? button on main gpuz screen) which then should show full x16 speed. Well they did with a 670 and 780ti. Not sure about 8x being reported before tho. Do you check when idle or when running something that kicks it to full use?

Amd vega56 shows x16 even in idle so presume amd cards differ that way.

The low res issue sounds like when your in safe mode or when a driver isnt installed.
 
Check the bios to force to gen3 or see if theres a bios update or it might be windows needs updating to 1909. Oh and check chipset drivers to see if latest?

Google came up with this topic, might help find some ideas, the op there tried all sorts but was the mb itself the issue as a replacement i think it was sorted it, or changing risers for gpu sorted another user there or a reset bios to defaults for another.

Diff mb but similar issues.

https://rog.asus.com/forum/showthread.php?97581-PCI-E-runs-at-x8-instead-of-x16

More topics if search using "z370 prime a pcie lanes x8" phrases.

Also found this:
https://www.reddit.com/r/intel/comments/a568tq/nvme_ssd_and_pci_express_lanes/

If u have such drives.

End of the day its nothing to worry about pci-e x8 is enough and shouldnt cause any speed issues in gaming etc.
 
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Thanks for replies.

Have checked drivers and bios - all were upto date with latest versions.

Set peg to gen3 in bios.

Am wondering if it's a bios setting to change it but have not found anything. The m.2 drives are set as nvme and not sata.

Could it be an error with the board maybe?
 
Had that recently but with a different board and card. Initially, it showed as PCI-E x1 (and performance in Wreckfest was dire but Heaven benchmark ran OK). Checked BIOS, power settings and all was fine. Ended up pulling out the graphics card and putting it back in - which than showed as PCI-E x8. Reseated again, and had x4 those time. Finally gave the contacts of the card's connector a wipe over, put the card back in and it finally showed as PCI-E x16. Wreckfest then ran perfectly, really surprised Heaven benchmark score didn't change!
 
Took my card out earlier and gave a wipe before I reinstalled but no change with gpuz still saying it's running at pcie X8.

Thank you SkeeterUK for re-assuring me that not any difference between pciex8 and pciex16.

I'm just putting it down to this board and having two m.2 installed. Apart from this the board is pretty good and seems a lot more stable than motherboards were 10 years ago when I was last building and using pc's.

Thanks to everyone for helping; am just going to accept situation until upgrade. Cheers.
 
malccy said:
Several times now and although not the clearest I think i've tried every possible setting option in the bios. Wish they would explain what things actually in the bios do rather than needing to google everything.
Click to expand...

The manual always has the wiring and how the slots would perform if some is occupied.

Tbh if you plan to upgrade and use M.2, get Ryzen :D
Even the upcoming Z490 is similarly wired to the Z370/390/270/170. Only 16 lanes 3.0 to GPU & first M.2 (so 8/8 if both conected)
While X370/470/570 are 16 lanes to PCIe slots, +4 lanes to 1st M.2 to CPU directly, plus the connector to the chipset.
 
Panos said:
The manual always has the wiring and how the slots would perform if some is occupied.

Tbh if you plan to upgrade and use M.2, get Ryzen :D
Even the upcoming Z490 is similarly wired to the Z370/390/270/170. Only 16 lanes 3.0 to GPU & first M.2 (so 8/8 if both conected)
While X370/470/570 are 16 lanes to PCIe slots, +4 lanes to 1st M.2 to CPU directly, plus the connector to the chipset.
Click to expand...

You sure?
I've got both m.2 occupied in my z370 and my GPU is still showing as 16x
 
dessimpson said:
You sure?
I've got both m.2 occupied in my z370 and my GPU is still showing as 16x
Click to expand...

Depends the motherboard wiring. :)
On mainstream Intel platform, only 16 lanes pcie ports are wired to the CPU. Some use that for the 1st M.2 others go through the chipset.

AMD has 20 lanes to pcie ports, plus the connection to the chipset. Of those 20 lanes, 4 for the first M.2, the rest to the pcie ports.
 
malccy said:
Thanks for replies.

Have checked drivers and bios - all were upto date with latest versions.

Set peg to gen3 in bios.

Am wondering if it's a bios setting to change it but have not found anything. The m.2 drives are set as nvme and not sata.

Could it be an error with the board maybe?
Click to expand...

Bios > advanced > PCH configuration > PCIE express configuration.

Should be able to force it to x16 here.
 
you didnt mention which cpu you have, just doing some digging and all 8th gen cpu's only have 16 pcie lanes total, the problem is the top m.2 between the cpu and gpu, its taking 4 lanes directly from the cpu which makes your gpu run at x8 instead of x16.

the lower m.2 will work at full speed but uses the chipset lanes, hence why some sata ports are disable when using it, as others have said you wont really notice a drop in performance with x8 pcie its just a limitation of the platform your on, here is a hany link i assumed you have a 8700k

https://ark.intel.com/content/www/u...8700k-processor-12m-cache-up-to-4-70-ghz.html
 
wookiee87 said:
you didnt mention which cpu you have, just doing some digging and all 8th gen cpu's only have 16 pcie lanes total, the problem is the top m.2 between the cpu and gpu, its taking 4 lanes directly from the cpu which makes your gpu run at x8 instead of x16.

the lower m.2 will work at full speed but uses the chipset lanes, hence why some sata ports are disable when using it, as others have said you wont really notice a drop in performance with x8 pcie its just a limitation of the platform your on, here is a hany link i assumed you have a 8700k

https://ark.intel.com/content/www/u...8700k-processor-12m-cache-up-to-4-70-ghz.html
Click to expand...

Thank you ever so much for clearing this matter as was begining to believe the motherboard had a fault. The cpu I have is an 8700 (no-K).

Would the bottom pciex16 be able to run at x16 - would I be better to put my gfx card there and would ther top m.2 run at higher speed then?

I really appreciate your time answering my problem.
 
malccy said:
Thank you ever so much for clearing this matter as was begining to believe the motherboard had a fault. The cpu I have is an 8700 (no-K).

Would the bottom pciex16 be able to run at x16 - would I be better to put my gfx card there and would ther top m.2 run at higher speed then?

I really appreciate your time answering my problem.
Click to expand...


i'm afriad moving the card will yeild the same issue because of the bottom m.2 you have there couple that with the chipset only having around half the lanes the cpu has you'd be running your card in x4 or worse x2 mode which isnt recommended, best off leave the card in the top slot, as said before and others running gpu's in 8x mode still provides enough performance in games, where it may count is in benchmarks, but it'll be marginal at best

malccy said:
Would the bottom pciex16 be able to run at x16 - would I be better to put my gfx card there and would ther top m.2 run at higher speed then?
Click to expand...


the m.2 wouldn't get a boost in speed if you moved the card, the m.2 will only use 4 lanes total. the m.2's controller wont go faster if it has more lanes to use, be really cool if it worked that way but in reality it wont and you may find the mobo wont post due to so little pcie lanes going to the gpu in a lower slot on the board.
 
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