AMD RX VEGA estimated safe Wattage PSU

Zeebedy · 14 Jul 2017 at 20:17

Hey guys,

after reading up on the VEGA thread, im really getting paranoid that my 650W G2 wont be able to sufficiently handle the RX VEGA XT GPU.

Would a 750W suffice or am I better with a 850W. This will not be on crossfire or anything as such.

EsaT · 14 Jul 2017 at 20:40

Unless overclocking CPU add 150W to graphic card's consumption and you get maximum power draw.
Though actual game load is going to be lower because games can't use all cores/threads of CPU.

No doubt there will be various overclocked versions but would expect standard models to be around 300W consumption.

FredFlint · 18 Jul 2017 at 10:30

If a 650W G2 cannot cope then VEGA is in real trouble.

Rannoch · 18 Jul 2017 at 10:32

I'll be wating for benchmarks before even considering that card.

Zeebedy · 1 Aug 2017 at 14:42

Hey guys,

Bit of a concern here..I have a evga g2 650w psu...

It has 2x 6+2 and 6 pin..so i cannot use one cable for the 2 8pin that will be coming on rx vega..

Am I ok to use the two cables and use the 6+2 on each one to make up the two 8 pin on the gpu?

Borealis · 1 Aug 2017 at 15:55

It's perfectly fine to use two cables with 6+2 pin connectors. In fact with a high draw GPU, I prefer using two cables as it reduces the load on each cable. That said, a quality PSU such as the G2 650W has cables capable of taking the full power draw. My 1080Ti is hooked up with 2 6+2 cables on a G2 850W. The only drawback to using more cables is that you then have to organise/tidy the extra cable.

Zeebedy · 1 Aug 2017 at 16:58

Borealis said:
It's perfectly fine to use two cables with 6+2 pin connectors. In fact with a high draw GPU, I prefer using two cables as it reduces the load on each cable. That said, a quality PSU such as the G2 650W has cables capable of taking the full power draw. My 1080Ti is hooked up with 2 6+2 cables on a G2 850W. The only drawback to using more cables is that you then have to organise/tidy the extra cable.

Awesome, just wanted to confirm, thanks mate!

EsaT · 1 Aug 2017 at 19:12

Borealis said:
It's perfectly fine to use two cables with 6+2 pin connectors. In fact with a high draw GPU, I prefer using two cables as it reduces the load on each cable. That said, a quality PSU such as the G2 650W has cables capable of taking the full power draw. My 1080Ti is hooked up with 2 6+2 cables on a G2 850W. The only drawback to using more cables is that you then have to organise/tidy the extra cable.

Seasonic actually forbids using one cable from PSU split to two power connectors of graphics card.

And voltage loss from too high current per cable/wire was apparently behind this reboot when under heavy GPU load problem:
https://forums.overclockers.co.uk/threads/ocp.18787566/

You have to remember that using fewer than intended wires for same current/power causes not only higher voltage loss to 12V leading to graphics card seeing lower voltage...
But also higher voltage loss in ground wires rising ground more above actual zero.
And that might be bigger problem than fluctuation of 12V input voltage:
8-pin PCI-e connector with its higher current/power rating than 6 pin connector actually doesn't have any more 12V wires, just more ground wires.