2 GPUS - 1 underrated PSU?

[Terminator_NL]

I am looking to upgrade my secondary graphics card (VirtIO passthrough) to a GTX 1080.

 

The system currently holds:

• CORSAIR CX Series CX650 650W ATX12V
• GTX 1060 6GB
• Shitty card I plan to upgrade: AMD Radeon HD 5450
• AMD RYZEN 7 1800X

 

The cards may or may not be used intensively at the same time (Virtual machine and Main).

 

Should I upgade my PSU, or do the graphic cards throttle themselves when there isn't enough power?

[OrionFOTL]

No, even a good 400W power supply would be enough. I misread, I thought you'd run HD 5450 and 1080. But yes, 650W is way more than needed for 1060 with 1080 too.

 

By the way, graphics cards can't sense whether the PSU is capable of supplying enough power or not. If the components draw enough power to trip the PSU's over-power protections, it shuts off.

[Terminator_NL]

Allright! Thank you for your time!