mlaningham
I have the 3090 FTW3 Ultra as well.  OC Clock +100, OC Mem +750.
I have a 1000 Corsair PSU.  On my APC, it has an option to show current wattage.  Doing a benchmark, I see it cross the 900 line fairly often.  I've not seen it go above 907.  
Without OC, the highest I've seen it hit was 793.  
I personally would reccomend the new Evga 1300 PSU they just released.  That's my plan for when I upgrade either when Zen 3 numbers come out, or in March when intel numbers come out.
Running 9900KS @ 5.3 as well.

 
Woah.. pulling 907W on a single 3090 FTW3 Ultra build is scary, even with an o/c. I recently purchased an EVGA 850 T2 for this new build, and I'm not going to be pleased if that isn't enough juice for a single 3090 and i9-9900k with reasonable overclock.
 
 

Nereus

mlaningham
I have the 3090 FTW3 Ultra as well.  OC Clock +100, OC Mem +750.
I have a 1000 Corsair PSU.  On my APC, it has an option to show current wattage.  Doing a benchmark, I see it cross the 900 line fairly often.  I've not seen it go above 907.  
Without OC, the highest I've seen it hit was 793.  
I personally would reccomend the new Evga 1300 PSU they just released.  That's my plan for when I upgrade either when Zen 3 numbers come out, or in March when intel numbers come out.
Running 9900KS @ 5.3 as well.

 
Woah.. pulling 907W on a single 3090 FTW3 Ultra build is scary, even with an o/c. I recently purchased an EVGA 850 T2 for this new build, and I'm not going to be pleased if that isn't enough juice for a single 3090 and i9-9900k with reasonable overclock.
 
 

After looking up the i9 9900k it shows 5ghz as max. so 5.3ghz has to be pushing some good wattage i would think.

Nereus

mlaningham
I have the 3090 FTW3 Ultra as well.  OC Clock +100, OC Mem +750.
I have a 1000 Corsair PSU.  On my APC, it has an option to show current wattage.  Doing a benchmark, I see it cross the 900 line fairly often.  I've not seen it go above 907.  
Without OC, the highest I've seen it hit was 793.  
I personally would reccomend the new Evga 1300 PSU they just released.  That's my plan for when I upgrade either when Zen 3 numbers come out, or in March when intel numbers come out.
Running 9900KS @ 5.3 as well.

 
Woah.. pulling 907W on a single 3090 FTW3 Ultra build is scary, even with an o/c. I recently purchased an EVGA 850 T2 for this new build, and I'm not going to be pleased if that isn't enough juice for a single 3090 and i9-9900k with reasonable overclock.
 
 

 
That's 900W from the wall...
 
Not from the PSU to the system...
 
Will be quite a difference depending on what PSU it is.
 
 

aciditty
If you have another PSU plug the GPU into it and run the system on the current PSU if it doesn't fail then your PSU isnt enough. 

I would never recommend this. Two separate power supplies is begging for trouble that could even damage components. I can’t guarantee smoke and burning smells but it having two power sources that mix on the card could lead to really wonky voltages. I would bet that results could also be dependent on make and manufacturer of power supply.
 
Unless this is known to work, nobody should try this.

arestavo

mlaningham
I have the 3090 FTW3 Ultra as well.  OC Clock +100, OC Mem +750.
 
I have a 1000 Corsair PSU.  On my APC, it has an option to show current wattage.  Doing a benchmark, I see it cross the 900 line fairly often.  I've not seen it go above 907.  
 
Without OC, the highest I've seen it hit was 793.  
 
I personally would reccomend the new Evga 1300 PSU they just released.  That's my plan for when I upgrade either when Zen 3 numbers come out, or in March when intel numbers come out.
 
Running 9900KS @ 5.3 as well.

If I overclock my VRAM to +1000 on my 3090 FTW3 with no 3D load at all, my computer reboots itself - on a EVGA 1600 watt T2 power supply.

So, you're likely pushing your card too far for the game (and if you enabled RTX in Metro Exodus, the game is using parts of the GPU that are otherwise turned off for non-RTX games and benchmarks - which means stability testing with RTX is needed). You could verify this by lowering the CPU overclock and testing the GPU again with the same game/OC.

 
Do you have reboot with jusr VRAM overclocking or VRAM plus core overclocking? What about just core overclocking.
 
And yes what you have described is exactly what I found. Instability is only found in RTX on games, also only happens when transitioning from a heavy RTX scene to a light RTX scene.

jaxkrabbit
I am also having problem exactly like this for my 3090FTW3 Ultra. I have a Seasonic Titanium 850Watt PSU. It only happens when I overclock with power slider maxed out to 107%, and so far it only happens in Metro Exodus. All benchmark seems fine.
 
Symptom is just as many has described: PC suddenly turns off, then reboots. In event manager it shows Event ID 41, Kernel-Power 63.
 
So what, I am going to need a 1000Watt PSU to power the 3090 now?? My UPS does show the at heavy GPU duty the system draws around 700Watt

I had this happen (same error in event manager) for the first time last night upon launching a game with my 3080 FTW3. I didn't even get into the game, just main menu loading caused the system to comletely shut down and reboot itself. GPU was at stock with power/temp slider max and fans at 70% but no actual overclock. I have had the GPU for a week and have gamed for hours and hours without issue so I don't think the GPU is faulty, maybe a driver issue. 
 
PSU is an EVGA 1600w T2 so I have my doubts that my PSU is the issue. 
 
Yes all 3 8 pin cables are separate cables. 

jaxkrabbit
Do you have reboot with jusr VRAM overclocking or VRAM plus core overclocking? What about just core overclocking.
 
And yes what you have described is exactly what I found. Instability is only found in RTX on games, also only happens when transitioning from a heavy RTX scene to a light RTX scene.

GPU core overclocking I'll just get instability if I push a little too far. VRAM, it will reboot when I set +1000 with absolutely no load. 
 
As to your instability in RTX games - you'll have to back off the overclock. FWIW, I have a profile saved for benchmarking, and one for gaming (both stable for what I use them for) - you could do something similar for RTX and non-RTX games if you wanted to.

Just plugged my card in that came this morning with the same issue. Clean driver install. New precision. Kinda wish I just stuck with my 2070 at this point. Now my thermal take 750 isn’t enough?! CPU is stock. Card is stock. What a bummer. PC just restarts randomly. Cool.

Bcassiman
Just plugged my card in that came this morning with the same issue. Clean driver install. New precision. Kinda wish I just stuck with my 2070 at this point. Now my thermal take 750 isn’t enough?! CPU is stock. Card is stock. What a bummer. PC just restarts randomly. Cool.

Thermaltake PSU.....
 
Not surprising at all.
 
 

After reading this thread I'm starting to worry...
 
I have an EVGA SuperNOVA G3 1000W 80 Plus Gold.