PCIe x16 GPU card into a PCIe x8 slot?

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Message 2072950 - Posted: 9 Apr 2021, 16:52:18 UTC

Here's one for the GPU experts...

Can I plug a x16 GPU card (AMD) into a x8 PCIe slot that is itself one of 4 x8 PCIe slots on a x16 PCIe riser?

There's no additional power connectors on the GPU so all the power will have to come from the PCIe.


Before I start hacking cases and brackets:

Any fire-raising gotchas?

Will it work?


Happy fast crunchin',
Martin
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Message 2072951 - Posted: 9 Apr 2021, 17:14:39 UTC - in response to Message 2072950.  
Last modified: 9 Apr 2021, 17:17:17 UTC

yes you can. is the end of the slot open? or closed?

see this x4 slot for an example of what i mean. the end of the slot is open and not closed off. PCIe devices are adaptable and can pretty much be installed in any kind of pcie slot. having half of the slot doesn't impact the ability to run, but it will limit total bandwidth to whatever you have it connected to (can't shove 16 lanes down a 8 lane slot without some PLX trickery)



if the slot is open like that, you should be good to go. if it's not open, you could a) use another riser to adapt the x8 to x16, or b) carefully cut the end of the slot open with a dremel and steady hand.

can you give some more information on what kind of system this is, what GPU it is, and what the riser is? from your description it sounds like a server chassis riser board.
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Message 2072977 - Posted: 10 Apr 2021, 0:44:14 UTC
Last modified: 10 Apr 2021, 0:47:22 UTC

Thanks for that.

Yep, it's an old Opteron server with a meagre 640x480 vga display. I happen to have an old rx560 that supports hdmi... So will be good to see something from them both!

Yes, can carefully open up the end of the PCIe slot. Also there's room to fit the x2 slot card. So well worth a giggle with linux.


Thanks for confirming the slot use.

This'll be no speed demon but should prove to be a good Frankenstein test!

Thanks,

Happy fast crunching,
Martin
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Message 2072981 - Posted: 10 Apr 2021, 3:03:38 UTC - in response to Message 2072977.  

Certainly less risky to cut up the riser than the slot on the board! I did the same thing on one of my systems (not for BOINC)

Good luck.
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Message boards : Number crunching : PCIe x16 GPU card into a PCIe x8 slot?


 
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