PCIe adapter riser card (low profile x16 to full height x8)?

Ouroboros

New Member
Jul 26, 2012
26
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Recently fishing around at oddball stuff, and noticed while there are many servers with full height x8 PCIe slots, there really doesn't seem to be proper low profile PCIe card adapters that behave as a PCIe pass through riser with lane reduction.

The closest things I found so far is Startech's x1 to x16 adapter, but that doesn't have a stub PCIe bracket to stabilize it, and there are complaints that due to it lacking auxiliary power, some x8 and x16 cards fail to operate correctly. Startech does have a PCIe full height to PCI LP adapter, which does have the stub bracket and aux power but being PCI doesn't do use any good.

Now the obvious thing is to just find the original full height PCIe bracket for whatever card you are having trouble with, but doesn't help anyone with an x8 slot without the rear cutout and an x16 card.

Do x8 to x16 LP to FH adapter riser cards exist that fit correctly, and possibly have aux power?
 

mb300sd

Active Member
Aug 1, 2016
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I could definitely use something like the first one, but it doesn't look like its the right height to fit a low card into a full height slot. Still useful though, I could always waterjet and bend up a custom bracket, but it's a lot more work.
 

Mithril

Active Member
Sep 13, 2019
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Did you ever find the exact thing you were looking for? I'd like to source some pci-e low profile -> full height adapters, useful for putting a 8x card in a 4x slot that isn't open ended, clearing components, etc.
 

T_Minus

Build. Break. Fix. Repeat
Feb 15, 2015
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I guess I've just gotten lucky and the x8 I need to put GPU in have open ends and just overhang and work as-intended just at x8 not x16 :/
 

Ouroboros

New Member
Jul 26, 2012
26
2
3
Did you ever find the exact thing you were looking for? I'd like to source some pci-e low profile -> full height adapters, useful for putting a 8x card in a 4x slot that isn't open ended, clearing components, etc.
I ultimately ordered some custom risers from a man well recommended on the HardOCP forums.

C_Payne: PCB Design & Prototypes

Mine had additional secondary power via a SATA power cable to cover x16 power edge cases (though I am probably overthinking it, but there had been reports of x16 to x8 or x4 lane reducer risers having trouble with GPU's that, while not needing a secondary GPU power connector, probably are near the edge of the PCIe power consumption envelope so I wanted to take no chances). Mine used Startech PCIe-PCI risers as donors for the LP-FH cutout bracket, increasing the price a fair bit. Note that keeping a LP bracket and fitting to a fullsize bracket with a cutout has a minor screw alignment problem (reversed left/right, so you will end up with the LP card riding on top of the adjacent card's bracket when screwing in).