[SOLVED] MSI X470 GAMING PRO MAX - is the 2nd CPU power connector really needed with Ryzen 9 3900 non-x?

[Piri1974]

Hello friends;

I just purchased a mobo-cpu combo consisting of a Ryzen 9 3900 non-x cpu,
and an MSI x470 Gaming Pro Max motherboard.

I noticed that this mobo has a second CPU power connector: one 8-pin (4+4) and another 4-pin.
Will I need to use that second 4-pin connector?
I have a cheap 550 Watt Corsair VS550 power supply here, and I was hoping that this should be enough... or should I buy a higher grade PSU to be on the safe side?
That PSU does not have a second CPU connector, only one 8-pin (4+4) connector.

I will use this pc only for number crunching, eg. the Mapping Cancer Markers project of World Community Grid.
The Ryzen 9 3900 non-x is a 12-core, 24-thread cpu with a TDP of 65Watt, and I will not overclock it.
So I will only use a basic video card to have my Windows screen: a Radeon HD6450, which is a 20 Watt TDP video card.

So, is it okay to leave that extra 4-pin connector empty, or is that not a good idea?

Many thanks in advance for your input.
Have a nice day;
Carl Philip

 

[BogdanH]

Yes, you can leave that additional 4-pin CPU power connector empty and every CPU will run just fine (well, my 5900X does).

 

[Piri1974]

Yes, you can leave that additional 4-pin CPU power connector empty and every CPU will run just fine (well, my 5900X does).

Ok, thanks for reassuring me.
I wonder if someone ever uses that 3rd 4-pin cpu power connector then... what's it for? For people who like to overclock? For High-wattage CPUs?
I guess my Ryzen 9 3900 non-x can do with just the 8-pin (4+4) power connector just fine.

 

[BogdanH]

According to specs I've found, even only 4-pin connector would suffice in most cases for AMD CPU's:
4-pin: ~160Wmax, 8-pin=~320Wmax
Ryzen 9 3900 consumes max ~90W (see here) so you're pretty safe

Why some "better" mobo's have 8+4 connector? Well... no idea, seriously. Because even Ryzen 9 5950X needs "only" about 180Wmax (see here). But then, maybe for those who use liquid nitrogen for cooling their beast