Powering 3090: Use 1 vs 2 PCIe 8 pin PSU Sources

philo-sofa · 13 Jan 2022 at 23:15

Hullooo chaps and occasional chapettes. I'm running a 3090 from a Corsair HX-1000 PSU.

The standard 8-pin PCIe cable from the PSU has two 8-pin plugs attached to it. However out of caution as I'll be pushing 400w I've run a separate 8-pin out of the the PSU, so effectively my graphics card is powered via two separate 8-pin plugs from the [EDIT] power supply.

Is this redundant and a bit silly? Always keen to reduce cable clutter if I can.

Rroff · 13 Jan 2022 at 23:37

Nothing redundant with the Ampere cards - they can pull some silly levels of transient power in spikes - I'd rather have the reassurance personally.

james.miller · 13 Jan 2022 at 23:49

philo-sofa · 14 Jan 2022 at 13:57

@james.miller @Rroff thank you gents, that makes sense. Two cable sources it is.

ODuffer · 14 Jan 2022 at 14:25

This is the recommend cable setup for a 3090 anyway?

philo-sofa · 15 Jan 2022 at 00:12

ODuffer said:
This is the recommend cable setup for a 3090 anyway?

Well that settles it even more securely, cheers. Out of interest where are these instructions from?

ODuffer · 15 Jan 2022 at 09:34

I got it from here(Actually advice from Sea Sonic?)

Also of interest

I'm not a fan of too many cables myself, I might get hold of one of these for my Corsair PSU.

EsaT · 15 Jan 2022 at 10:35

philo-sofa said:
However out of caution as I'll be pushing 400w

3090's transients are near 600W level and overclocking likely pushes those further.

philo-sofa said:
Well that settles it even more securely, cheers. Out of interest where are these instructions from?

There have been actual cases here on UcUK forum with use of single daisy chained/split from GPU end cable causing problems solved by switch to two separate cables.

philo-sofa · 15 Jan 2022 at 12:55

Cheers all. For now will use the dual 8-pin to 12-pin setup, but have also ordered a custom white modDIY white dual 8-pin to 12-pin cable to simplify things a bit down the line.