I got an RTX 3090 (Asus Strix OC) start of the year when prices were heading upwards. It has had a lot of issues. Black screen, system crashes etc. I started to water cool it (active backplate as well) and it did help with VRM temps but they were still issues during certain gameplay.
I came across this video from jaztwocetns on issues with certain games that I do not play but have caused these cards to catch fire. I am not surprised given how bad the entire 30 series is.
He recommends some good ideas. One that caught my attention was power usage. I use T-Rex mining to test my cards. note: He mentions 3090 is 350 Watts but maybe he was referring to FE because mine is Asus Strix and it easily goes above 350 W when used in P Mode I have never tried the Q Mode which I assume is quiet mode.
Prior to Water cooled front and back plates, I would see overheating when mining so it would result in black screen and restarts. I was never able to get much info.
After water cooling.
I was seeing some 388 Watts power usage at default mining intensity of 22. So anyway I started to lower the max power by 5% and reached 80% with no noticeable drop in mining performance.
Here are the results at various power levels.
Ambient temp is around 29 degrees Celsius.
No Overclocking is being used. I have included MSI Afterburner screenshots.
power usage: 388 W I can easily push this higher without OC in certain games. I believe this when 3090 shits its pants.
Energy efficiency: 255-270 kH/W
Hashrate average 100MH/s (estimate, see Graph below, hashrate drops)
_temps: 48°C Core and 84°C VRM
80% of Max power
power usage: 310W I’ve reduced by almost 75 Watts here, thats like a 1060
Energy efficiency: 335 kH/W
Hashrate average 107MH/s (estimate, see Graph below)
_temps: 40°C Core and 78°C VRM
Cool temps and actually stays at below 80°C for *VRM temps
Graph of power versus average hashrate.
9 hours of Total test duration in underclocked mode.
Conclusion: reduce power usage safely by 20%, improve stability without sacrificing noticeable performance. Might even improve
I will update the posts with more tests as I under clock.