Question PCIe Riser Cable performance hit?

[bdrmachine]

I have a ASUS Zenith Extreme Alpha+ MB and a RTX 3090 GPU. Like a lot of MB's the M2 connectors are under a heat spreader that requires removal of the GPU to access. If I used a riser cable this would allow easier access but, is there a measurable performance hit with this approach?

 

[SkyNetRising]

Which model ASUS Zenith Extreme Alpha ? X399 or TRX40 ?

If you have PCIE 4.0 board, then you also need PCIE 4.0 compatible riser cable.
With PCIE 3.0 riser cable you'll have issues.

 

[Karadjgne]

M.2 drives are best as 'set it and forget it' drives, so access physically has never been a priority. So not sure why the need for access.

As far as limitations, a direct connection is Always best, every further connection like a riser cable can carry a detriment. Pcie4.0 risers should be no longer than 6", or you start losing bandwidth. There's also power connections in that riser, the possibility of oxydation or other means of making a bad connection that affects performance.

So Can a riser reduce/affect performance? Absolutely. Will it? Depends on the riser, the load, the quality of build, nearby power source rfi/efi etc.

 

[bdrmachine]

Which model ASUS Zenith Extreme Alpha ? X399 or TRX40 ?

If you have PCIE 4.0 board, then you also need PCIE 4.0 compatible riser cable.
With PCIE 3.0 riser cable you'll have issues.

TRX40

 

[bdrmachine]

M.2 drives are best as 'set it and forget it' drives, so access physically has never been a priority. So not sure why the need for access.

As far as limitations, a direct connection is Always best, every further connection like a riser cable can carry a detriment. Pcie4.0 risers should be no longer than 6", or you start losing bandwidth. There's also power connections in that riser, the possibility of oxydation or other means of making a bad connection that affects performance.

So Can a riser reduce/affect performance? Absolutely. Will it? Depends on the riser, the load, the quality of build, nearby power source rfi/efi etc.

It would be great to be able to install all the drives and forget it but, I sunk a lot of money into this TRX40 computer and 4Tb ssd's weren't in my budget at the time. Both CPU and GPU are on a separate water loop. With at said , I would like to avoid the draining and refill hassle once and for all by relocating the GPU.

 

[SkyNetRising]

TRX40

Then PCIE 4.0 certified riser cable is necessary.
Or you have to force PCIE slot into PCIE 3.0 operation mode.

 

[Karadjgne]

With a dual rad full custom loop stuffed into a true mITX case, you are preaching to the choir there brother lol. I fully understand the situation with the M.2, mines not only buried under the gpu, but also at the bottom of the stack that includes the audio daughter board. (Asus X570-I).

So, instead of pulling the loop apart, would a pcie M.2 adapter in a lower pcie 3.0 slot not work? They come in single, dual or quad layout, this would leave your loop and your OS alone on the pcie4.0 card, and adaptable/expandable storage within easy reach. Negating the possible downsides of the riser and/or cloning process and negating any possibility of leaks, changing tubing lengths etc.
Like this.

 

[bdrmachine]

With a dual rad full custom loop stuffed into a true mITX case, you are preaching to the choir there brother lol. I fully understand the situation with the M.2, mines not only buried under the gpu, but also at the bottom of the stack that includes the audio daughter board. (Asus X570-I).

So, instead of pulling the loop apart, would a pcie M.2 adapter in a lower pcie 3.0 slot not work? They come in single, dual or quad layout, this would leave your loop and your OS alone on the pcie4.0 card, and adaptable/expandable storage within easy reach. Negating the possible downsides of the riser and/or cloning process and negating any possibility of leaks, changing tubing lengths etc.
Like this.

Great suggestion! Thanks