EVGA RTX 3080 FTW3 Ultra Gaming + XOC Bios and pulling the full 450w.
 
Thermaltake Toughpower iRGB Plus 1250 80+ Titanium works perfectly fine.. well it should for a.. 500€? PSU.. Thank god i got it for 180€ 

RTX 3060 Ti + RTX 3090 FTW3 Ultra Hybrid

• BeQuiet! Straight Power 11 (1000W) Platinum
• Note: The 3060 TI FE (130W tuned) typically mining while I game with the 3090, but when I have the 3090 mining, its typically rests at (310W)

RTX 3080 FE + Gigabyte 3060 TI OC

• Corsair AX760 (760W) Titanium
• Note: Dedicated Mining Rig - 3080 FE @ (230W) and 3060 TI @ (130W)

3080 FTW3 Ultra
Fractal Design Ion+ 760P
Working for about two months now. Had black screen video crashes yesterday but it was the extension sleeved cables I got from Formuladmod. Snugged the cables tight and it's back ON good!
Didn't see the Ion+ added to the list on post#1.

Seasonic Titanium Ultra 850Watt DOES NOT work. I would black screen during very specific workloads and proceed to restart.
 
Seasonic TX-850 (The newest tianium lineup) so far seems to work OK.
 
 

2x 3090 FTW3 Ultras
Corsair HX 1200
Rock solid for 9 weeks.
 
I did run a 220v 20A line to my office as this rig would occasionally blow my 110v 15A breaker.

Pwnstix
I'm one of the people who listed a Seasonic TX-1000 as working with my RTX 3080 FTW3 Ultra. Now, I'm not so sure. I've been experiencing reboots when under load, somewhat randomly. At first, it was only happening with Cyberpunk 2077, but I could consistently replicate the problem with OCCT's 3D stress test. Then it started happening more often, in games which do not put a lot of stress on the system, such as Heroes of the Storm and Europa Universalis IV.

I RMA'd the card, hoping that would fix it. It started happening again not long after I installed the replacement 3080.

I've posted about this in these forums before. I've tried everything I can think of, and I've come to the conclusion that either my motherboard has some kind of issue, or that this PSU, which has been in use for the same amount of time as my first 3080, can't handle the transient power spikes from the video card.

I thought I'd read that the TX-1000 revision had improved transient response over the older model SSR-1000TR, and I've even seen people posting about changing their PSU to the TX-1000 to fix this type of issue. Either my particular unit has problems, or there's something else wrong with my system.

Unfortunately I can't get a larger PSU because there are none in stock.

What CPU do you have? I ask because some combinations of Ryzen 3000 series and mobo's have random reboot problems (mine did).

Edit: I have a Seasonic Focus 1000w that works fine with my 3090, even at 500+ watts.

talon951

What CPU do you have? I ask because some combinations of Ryzen 3000 series and mobo's have random reboot problems (mine did).

Edit: I have a Seasonic Focus 1000w that works fine with my 3090, even at 500+ watts.

i7 8700K
 
If I do manage to get another power supply unit, I'll update my post again.

MAINGEAR IGNITION 1000W Platinum

3080 XC3 Ultra - No issues

AMD 5800x

Well, the issues I was having were getting worse, and so I went ahead and built a new PC build (updated my signature). I have the same Seasonic Prime TX-1000 PSU. Everything seemed fine at first. I'd been running stress tests, particularly OCCT's 3D stress test. It was passing. This is the 5th day I've had it up and running with the new components. I ran OCCT 3D test again today, and my PC shut down. So... I'm pretty much convinced it's the power supply, at this point. 
 
Back before, with my old build, I had upgraded from a Seasonic Prime Titanium 750W PSU, which wasn't that old, to this Seasonic TX-1000, just in case the RTX 3080 was more demanding. Apparently, that wasn't enough. When I was troubleshooting with the old build, I swapped my 750W back in and had the same issues. So, at first, I thought it was a video card issue--I RMA'd my first 3080 FTW3 Ultra. This is the 2nd 3080 FTW3 Ultra I've been using. 
 
My case airflow is fine. This case I'm using was made for airflow. I'm using 7 140mm case fans: 2 are front intake, 2 are bottom intake, and I've got 1 rear exhaust and 2 top exhausts. I've tuned them so that the intakes run at higher RPMs, so there's more fresh air coming in over all my components, with plenty of exhaust to expel heated air. I monitor my temperatures regularly. I know it's not overheating. The PSU is in its own compartment on the other side of the case. 
 
So either I've had two FTW3 Ultras with some kind of problem, or both of my Seasonic Titanium PSUs have issues. I know that my older Prime Titanium 750W is an older model (SSR-750-TD) which was later revised (SSR-750-TR). And I'd read that the 1000W was also revised, but my model, TX-1000 (SSR-1000-TR) is supposed to be the newer one with the improved transient response. 
 
But all of this is academic, at this point. There's simply zero stock of PSUs out there, so I couldn't get a replacement anyway. And if I were to RMA this PSU, Seasonic would probably send me exactly the same model, and I don't know if it would work, or not. I really don't know what to do at this point. 
 
edit1: I ordered an EVGA P2 850W PSU. I would rather have had a 1000W, but there were none in stock. I hope I don't regret downgrading to 850W from 1000W, but the EVGA P2 850 gets really good reviews, is built on a Super Flower Leadex platform, and from what I've read, has really good/excellent transient response. I needed to do something, as I just found my PC had shut off again while idle. That's only happened twice now, so far, on two different builds (happened once on my i7 8700/Z370 build in the last week before I upgraded my components to what I've got now). If this doesn't fix it... I don't know, maybe it's my wiring in my house, or this electrical socket, although I figured my UPS would catch any voltage drops, as it does when there's a brownout. I'll update again in a while, after I get and install the P2 850. 

Just got an EVGA Supernova G5 1000watt, and it works with my 3080 FTW3 Ultra. No overclocking. 
Asrock x299 taichi MB
Intel i7 7800x CPU
32GB 
3x SSD
No troubles at all. Old PSU was Thermaltake Toughpower Grand 850watt gold, and it still works... on every other system and configuration I throw at it, and it tests fine. Oddly the 3080 caused it to power off/on anywhere from 5 mins to 1 hour into any game. 

ROG-STRIX-RTX3090-O24G-GAMING Powered by Thermaltake Toughpower DPS G RGB 1500W Titanium Model: PS-TPG-1500DPCTUS-T 

I know my unit is already on the front page - but just to confirm.
 
 EVGA SuperNOVA 1000 G+ PSU   / Nvidia 3080 FE  = 4-5 months working great.

This thread has my Thermaltake Toughpower GF1 ARGB 750W 80+ Gold
shaking now, got a 3885 coming but eventually want to get a 3080ftw. 
Thanks for making this thread.

Retired = 2012 Seasonic Platinum-1000
Hint:  If your PSU is 4th gen compatible Haswell, it's time for a new PSU.
 
Full system upgrade to Z490 with a 3090 resulted in system shutdowns, no BSOD.  The system functioned correctly with the 1080 FTW installed, but it could not handle the RTX load.  I expected that it would be a problem (under load) and it was.
 
Corsair AX1600i has been flawless.  I got lucky and found one in stock.

 Got a 3080 coming tomorrow, do I need to take my pcie cable extensions off? 
Would hate to lose them as they are dayglow green ones and look really nice in my TT core p3 case.