Hard power off with 3090 under load

[EirePlane]

Not sure if this should go here or in Power Supplies

Picked up a Inno3D GeForce RTX 3090 iChill X3 a couple of weeks ago as part of a new build, but whenever I put it under a heavy load - especially in VR - the whole PC powers off suddenly.

I've got an 850W power supply (Bitfenix Whisper M), greater than the recommended 750W so I thought it would be ok, but do I really need a 1000/1200W PSU instead, or is the card drawing more power than it's supposed to? It hasn't been overclocked

I've run GPU-Z and it seems to be drawing way more than the 40W per rail the PSU is rated for, but perhaps I'm not reading it correctly



Am I right in that I just need a better PSU, or is here anything I might be overlooking?

 

[EirePlane]

Only 40 AMPS per rail. You want 70A rail(s)+ ideally.

That's what I was thinking, but surely a 750W PSU would be even worse?

under load crash can be a sign of the psu, did it do it before you upgraded on the old card first? what was in there prior. ive seen a list by evga where people where running the 3090 on the 750w version of your psu/

what else is in the system?

edit: yea 40a 12v rails might be the issue.

It's all brand new. There's a Ryzen 5800, two NVME Drives and a WiFi card

Your 850 should be fine how old is the power supply?
are you using 2 separate pcie cables or 1 ?

Two separate cables. Does the same if I have them on the same rail, or two separate rails too.


I'm inclined to agree with you all that the PSU is just underpowered, just wanted to double check that kind of power draw was typical for a 3090 before I fork out for another PSU

 

[EirePlane]

It's not about the power rating, you just want to find one that can sustain peak current the 3090 requires

Plenty of 750 and dare I say it 650W PSU's with stronger 12V rails than yours. It's not just the wattage, Rail amperage is where it's at. Your Bitfenix may say 750W but it's done across 2 rails of 40A with some switching between them. DUal or single rails are best when they are 70A+. Those EVGA 750W's that someone mentions above are 62A RAils so that's why they are running 3090's on 750's. 850W are 70A, 100W is 90A and, 1200W are 100A rails normally.

I remember reading some time ago that you want to be looking for a PSU with a 70A rail+ for GPU's with more than one 8 pin connector as weaker rails cause instability. You are better off with a single 70A rail than multi 40A rails.

Good to know, thanks guys.

Given that the GPU-Z data shows the card pulling 70A+ of power on each 8 pin connector (currently set up on a rail each), would an 80-100A single rail PSU be sufficient? Or do I need to be looking for something that can supply two 80-100A rails?

 

[EirePlane]

Some PSU's allow you to change them from multi rail to single rail. DOes that Bitfenix allow you to do that. Bitfenix arent known for their PSU's.

Only other things to test are RAM seated correctly and run at stock speeds (2400Mhz) if you have fast RAM, re-seat the gfx card in the mobo as I think some power is drawn from the mobo across the PCI-E. Yeah recheck ALL connections. Run afterburner to log file (so you can look on reboot) for temperatures on the MOBO, GPU or CPU. They 'could' cause a shutdown - before you buy another PSU.

List out your whole build. Ryzen's and their RAM can be finickety things. What RAM & MOBO?

I've seen a couple of Corsair ones that do that, but I don't think this Bitfenix one does. I'll double check all the connections and everything inside, but for the most part everything works fine, even under a reasonably heavy load. The problems only really happen if I use VR or anything else particularly intensive
CPU is getting up to about 70C at it's highest, but I'll check in afterburner too in case it's happening when I can't see temps


Build is below. VR Headset is Oculus Quest 2

Gigabyte X570 GAMING X (AMD AM4) DDR4 X570 Chipset ATX Motherboard
MB-57X-GI

Bitfenix Whisper M Series 850W 80 Plus Gold Modular Power Supply
CA-22D-BX

Corsair Force MP600 series 1TB NVMe PCIe Gen4 M.2 Solid State Drive (CSSD-F1000GBMP600)
HD-068-CS

TP-Link Archer TX50E Dual-Band Wireless AX3000 (WiFi 6) Bluetooth 5.0 PCI-E Adapter
NW-222-TP

Inno3D GeForce RTX 3090 iChill X3 24GB GDDR6X PCI-Express Graphics Card
GX-07K-IN

Arctic Freezer 34 eSports White CPU Cooler - 120mm
HS-071-AR

AMD Ryzen 7 5800X Eight Core 4.7GHz (Socket AM4) Processor - Retail
CP-3CB-AM

Patriot Viper Steel 32GB (2x16GB) DDR4 PC4-28800C18 3600MHz Dual Channel Kit (PVS432G360C8K) - Currently running at default speeds
MY-107-PA

WD Blue SN550 2TB NVME M.2 2280 PCIe Gen3 Solid State Drive (WDS200T2B0C)
HD-57N-WD

MSI OPTIX MPG341CQR 34" 3440x1440 VA FreeSync 144Hz 1ms Curved LED Backlit Widescreen Gaming Monitor
MO-00Q-MS