PSU and x570 CPU requirements

[mutantaxe]

I see the MSI Ace x570 has 2 x 8 pin CPU power "sockets" to plug into as you can see



And I see quite a few have 8pin and a 4 pin sockets for CPU power. But the manuals really dont give you much of a clue if you need to plug both in or if you can just use the one 8 pin cable.

Now I think my psu can supply 2 x 4+4 CPU power as pci-e and cpu both use the same 12 volts



So if I get another cable can I just plug it into one of these sockets on the PSU ?

Or getting a 2nd CPU power cable is overkill and not required?

I can order 2 cables from cable mod I guess but as you can see I really dont have a clue about this matter

 

[grec]

You can use a single 8-pin, it's capable of delivering 235W stable, so even an OC'd Ryzen9 CPU will be fine. If you want to use two EPS 8-pin cables, this would deliver slightly higher efficiencies and better stability(Less voltage drop) as the current per pin is halved(And wire losses are proportional to current squared), while increasing maximum CPU power delivery above 235W if you're heavily overclocking a 16-core or something. So no real downsides to using two if you have them, but no real need to either with a part rated at 105W, or much in the way of tangible benefits if it's going to cost you.

NOTE: PCIe 8-pin and EPS(CPU) 8-pin are completely different(Wiring/pin out, current capacity, and physical keying) on the output/board connection end and attempting to use one in the other can cause permanent damage so definitely don't go cramming a PCIe 8/6+2 pin into there.

 

[AlienALX]

You shouldn't need both but by all means connect them if you can.

I've had a few PSUs with only one 8 pin, so I just used to convert one of the PCIE into a EPS. It's only 12vs and grounds.

 

[grec]

You could use (Or rig up, the pins are quite easy to move around with bullnose tweezers) a passive adaptor wire(PCIe 8pin-> EPS) though you'd only get 3 of the 4 current carrying pairs. Some motherboards have 8-pin PCIe slots(Usually for increased current to the slots/fans/ect though or ones pinned for both but this one is explicitly two EPS slots for the CPU.

If you were to physically fit a PCIe 8-pin in the way the physical keying would (Almost) allow you'd end up with all the ground and 12V lines the wrong way round (Your motherboard probably has all the protection required to come out of that undamaged as I'd assume it's not too uncommon for someone to try, but I wouldn't risk your hardware testing that one out)

 

[mutantaxe]

yes, I dont think I will be pulling cables part

anyway, problem solved as reading the specs for my psu it says it has 2 of these cables and somehow one got lost from the bag but I found it in amongst a crate of cables and pC parts that I have.




so since I now have 2 cables I will use both

 

[grec]

Yeah that's the best choice if you have both, though that "IMPORTANT" notice is trying to say you should make sure all connectors you're using are fitted securely to an ATX PSU (IE you've not got wires dangling out or ghetto rigged or anything) so yeah it has no bearing on warranty how many wires you use if you do have to go to 1 any time in future.