Question PSU with 2x8 for GPU requiring 3x8

[st_ryder]

My PSU EVGA SuperNOVA 650 P2 Platinum has - 2x 8pin (6+2), 2x 6pin PCIe cables.
Just ordered rtx 3080 that requires 3x8 pin connection. Am I screwed and need new psu?

 

[sizzling]

Which exact 3080? While you can run lower power demanding 3080’s on a high quality 650w if the cpu requirements are low these 3080’s usually only have 2x8 pins. The higher power draw 3080’s would be too much for a 650w, these are usually the ones with 3x8 pins. I strongly expect you need a psu upgrade but without full pc spec it is speculation.

 

[st_ryder]

GPU is MSI RTX 3080 Gaming Z Trio 12GB. specs say it needs 3x8 pins.
all tests show PCs with this card require 550-600w. so 650w should be fine.
main problem is connector cables which I have only 2x 8 and 2x6 pins.

 

[sizzling]

GPU is MSI RTX 3080 Gaming Z Trio 12GB. specs say it needs 3x8 pins.
all tests show PCs with this card require 550-600w. so 650w should be fine.
main problem is connector cables which I have only 2x 8 and 2x6 pins.

I run a 3080 Gigabyte Gaming OC with a high quality 650w but the CPU’s I have used are fairly low power (3700x then 5800X3D). The trouble is the transient power spikes with these 3000 series card. Generally people recommend a 850w psu for a 3080 as there are good quality 650-750w that just cannot handle the spikes.

That 3080 seems to be exceptionally power hungry, it’s peaking at about 50w higher than a regular 3090.

Ultimately adapters are a bad thing and not recommend, for this alone you need a psu upgrade.

https://www.techpowerup.com/review/msi-geforce-rtx-3080-suprim-x-12-gb/36.html

 

[st_ryder]

yea looks like I need an upgrade

 

[rolli59]

yea looks like I need an upgrade

Yep for a card like that people recommend 850watt quality units because of transient load spikes that lower wattage unit do not handle very well.

 

[geofelt]

Contact EVGA for an authoritative answer to your question.
Usually using adapters is not recommended.
I doubt they would approve.
You would have to use a 2 6 pin to 8 pin pcie adapter.
Past that, 3000 series cards may have high power spikes, past the nominal requirement.
Lastly, you did not mention your cpu.
Modern processors can draw quite high peak loads.

I would be prepared to buy a much stronger psu.