Zotac 3090 with 750W

[AyaanMAG]

Hello folks, i built my pc just today with a ryzen 5 7600, an MSI MAG 750BN PCIE PSU and a Gigabyte Aorus Elite AX V2 Motherboard, my use case is more AI than gaming and i wanted a card with a good amount of VRAM, i found a deal for a Zotac RTX 3090 24Gb, however looking into it, the card draws like 350W of power which leaves me with two concerns

 

With the current components, can i run the card in my system or did i make a bad assumption and will need a new PSU, what is the likelyness that this will cause instability to the point of crashing, will it be fine if i dont draw them both at max at the same time?

 

And for my second question, how will i even power it? i, pretty sure i have one of those PCI-E (6+2 PIN) cables and a PCIE 5 300W with 16 pins

(https://www.msi.com/Power-Supply/MAG-A750BN-PCIE5)

 

Can i use an adapter for PCIE5.0 12VHPWR cable to pcie 6+2 pin and use the other free one for the other slot so that i can provide it more than 300W?

[--SID--]

1 hour ago, AyaanMAG said:

MSI MAG 750BN PCIE

Why this low end PSU when you have a high end GPU. You definitely need a better unit with at least three 6+2 pin PCIe connectors. Adapters are not recommanded.

[thekingofmonks]

If it's not a 12VHPWR card, you absolutely want to use native 8-pin connectors for safety.

 

21 minutes ago, --SID-- said:

Why this low end PSU when you have a high end GPU. You definitely need a better unit with at least three 6+2 pin PCIe connectors. Adapters are not recommanded.

Nvidia rates the 3090 as suitable with 750W power supplies, they even tested it with a 10900K. Most people have had no issues with it. OP's 7600 draws much less.

 

[igormp]

WIth the 3090 at 350W, the remaining of your system should not even draw 200W, so even a 650W PSU ought to be enough (I've ran my 3090 with a 650W PSU for quite some time without issues).

 

If you're worried about anything, you can just reduce the power limit of the GPU. A 3090 reaches its peak efficiency for compute at 250~280W, more than that and you'll be using way more power for diminishing returns.

 

1 hour ago, AyaanMAG said:

And for my second question, how will i even power it? i, pretty sure i have one of those PCI-E (6+2 PIN) cables and a PCIE 5 300W with 16 pins

(https://www.msi.com/Power-Supply/MAG-A750BN-PCIE5)

That cable has daisy chain, if you're brave enough you could just use it, but it's not recommended.

If you can find a 12VHPWR to 8-pin adapter, then it'd be perfect.

 

[Skiiwee29]

Wattage isn't the problem with the 3000 series, the transient spikes are. So even if you have enough Wattage, you likely don't have overhead for the transient spikes. My 3090 would trip my HX850 with its Transient spikes. I had to upgraded to an HX1200 to ensure I had enough overhead to be able to comfortably handle them.

[igormp]

6 minutes ago, Skiiwee29 said:

Wattage isn't the problem with the 3000 series, the transient spikes are. So even if you have enough Wattage, you likely don't have overhead for the transient spikes. My 3090 would trip my HX850 with its Transient spikes. I had to upgraded to an HX1200 to ensure I had enough overhead to be able to comfortably handle them.

Modern PSUs should handle such transient spikes without issues, specially the ones rated for the new ATX standards.

Setting a power limit also solves this issue, specially when dealing with compute workloads instead of gaming ones.

[GuiltySpark_]

Its all down to the quality of the PSU. I ran a 3090 @ 400W for 2 years on a Corsair SF750 SFX PSU. However, that particular unit is very highly regarded as well made PSU.