Thanks for your reply.
When I disassembled my old system, I found out that the PSU actually has two connectors for the CPU, but they both come out of the same output on the PSU (so this might be some sort of 'splitter'.
The PSU isn't too young: 6 years 1 month. I have a rtx2080 super. Doesn't look like I'm fine!
I dont know what the power draw on a 2080 super is, why not look it up?
Chances are your 650w PSU will be fine, its up to you weather you want peace of mind, then fine, buy a new one. But chances are that one is fine, lookup the power draw of the GPU and CPU, correct me if I am wrong, but both normally run off 12v these days, and assuming the PSU has a single 12 rail, you can do it in watts peak draw if you want, or amps, I prefer amps personally but sometimes it hard to find the draw of thigs in that, yes you can work it out using that trangle thing I can never remember.... - anyway, find out when the max both will draw, found out what your power supply can provide on the 12v rail, add a bit of extra for margin.
Infact:
2080 super - 280 Watts (thats an absolute overclocked heavy load max apparently on a google search)
12700k - 190 watts - again, described as the max
Total 470 watts as an absolute max.
649.2W is the max output on the 12v rail according to the manufacturer spec on the PSU.
So you've got about 180w of head room, and even then, at the point, both GPU and CPU would both have to be at absolute extreme max load.
EDIT: There you go, 38amps draw vs 54amps provided.
Double check the above power draw figures on the CPU and GPU because I only did a brief google of them.
eDIT 2: wow, according this your PSU is still under warranty just about:
https://www.evga.com/products/specs/psu.aspx?pn=ad867852-b490-4a07-9974-8016e58dd60c
IF it helps, I am using a 10+ year old Corsair HX850 in my current build.