I have had the unfortunate displeasure of dealing with 2 broken 3090 FTW3 Ultras, and upon the issue happening yet again with my 3rd card, I decided to do some deep trouble shooting. Let me lay out the experience for you.
I enjoy playing older titles, as well as the newer AAA titles from time to time as well. My first 3090 did great in demanding games, but was netting me a subpar overclock (+75 Core/+500 Mem), I played 100+ hours in Cyberpunk 2077 and I really had a great time. However, I was getting black screen high fan spinning usage when playing less demanding titles such as League or Halo MCC. I had to hard reset my computer to get the card to turn back on, and I did so over the next few weeks whenever I played those games, until one day, it wouldn't turn back on at all. I had no lights on the card, and a red light over one of the PCIE power pin slots.
I RMAed. The new 3090 came, and I was happy. 50 more hours of Cyberpunk, and no issues. But in League....more crashing. 6 more black screens later, the 2nd card was dead. Red light over a PCIE pin power slot, but the card still lit up. Not sure why about that.
My 3rd card came yesterday. And I knew right where to look. The reason that doctors press until it hurts is to find out where the problem is, because patients sometimes lie.
I launched League and without 3 minutes going by in game, black screen, high fans, no output, and the card was running at stock speeds. I called up EVGA, and I had a nice long chat with a rep while I tried to reproduce the issue. They told me the symptoms I was experiencing were "Over-Current Protections" kicking in, and also that my first RMA card had failed because of a power related issue. They suggested I switch out my power supply (an EVGA 1200W P2) with the gold power supply I had before (EVGA 1300W G2). I played a full 16 minutes of league while on the phone with them, and experienced no crashing, but a minute after we hung up, it black screened, and crashed again.
Now, I dabble in overclocking quite a bit. I'm aware of how voltages can cause instability in cards, and how too much current breaks transistors and traces inside CPUs. I'd never had this issue with GPUs before, because I would always just do mild overclocks.
So I started using GPU-Z to watch my voltages while gaming on League. What did I see while playing League? Well, the card would *usually* be at 1800 Mhz, using 0.8680 V while I was in game, but occasionally, the voltage would spike along with the clock speed, all the way up to 2025Mhz and 1.0810 V. Now, I like I said, I don't do much "hardcore" overclocking for my GPUs, but I have used MSI Afterburner for literally 10 years. I've never seen a video card go over 1.050 Vs. I looked up the max safe voltage for the 3090, and wasn't able to find it using google, but I had another solution that I knew would work.
So, I booted up Cyberpunk, since I knew I could game on that for hours on end without crashing. Max Voltage I saw in that game? 1.050V. Played fine for an hour. Then I thought to myself, let's try overclocking? So I set my power limit to 107%, with a mild OC of +75 Core and +750 Mem. 1.075 V when the game started, and 1.068 V while in game. Ok....Let's crank the overclock. +150 Core and +1500 Mem. Played fine for another hour, still max voltage in game? 1.068 V.
I then had a thought. What if the voltage curve in lower power states is messed up somehow? I set MSI Afterburner to "Force Constant Voltage" and booted up a League custom game. I was able to play the game for 35 minutes before the game crashed, so I knew I was on the right track. There were less voltage spikes, and less core Mhz spikes as well. But it still crashed? Why? Well, when it finally did crash, it had gone up to 1.081 V again. https://prnt.sc/yla8ib
The fix? Voltage curves.https://prnt.sc/ylaaor
As you can see here, the normal voltage curve stops ramping only when the card gets up to a whopping 1.118 V on the core. Well, I'm crashing at well below that at using only 150 watts and the core at 1.081V, and I know the card is stable using 450 Watts at 1.068V so what can I do to fix this?https://prnt.sc/ylahyd
I set the core Mhz to plummet after 1.068 V, and since I'm not getting anywhere near those higher voltage numbers without a higher power limit BIOS, I don't need to worry about them.
The result? I just streamed and watched a movie on my 5 monitors while playing a 2 hour custom game of League by myself. I'm going to need more testing, but I believe I've fixed the problem.
EVGA needs to adjust their voltage curves for the standard BIOS, because I believe it's breaking Voltage limits in lower power states while still attempting to go to higher core clocks. Also, while my experience here is only anecdotal, it *has* fixed my League crashing problem, so I can only assume that the voltage curve *is* the issue. The card attempts to go up to a voltage it shouldn't be at when the temperature is not low enough on the card to do so, breaking copper traces in the card with too much voltage at too high of a temperature.
While my experience here is a solitary thing, I would like to have some other people experiencing this issue chime in, and let me know if this fixes the issue. Maybe I've fixed EVGA's RMA problem with these cards, an experience that I can only assume has reached a large dollar cost figure, with how many people I've seen having the same issues.
EDIT: While I fix my images.
EDIT 2: For those that don't feel like reading through the entire thread, the problem was fixed by limiting my voltage for OC to 1.062V and below, and having the card run at stock speeds at any voltage above 1.062 V. Comfortably running at +120/+1250 for about 5 days with no crashes. While you obviously shouldn't have to do this sort of workaround to prevent your card from dying, I can say with confidence this solves whatever issue is causing game crashes and constant RMAs. Happy Gaming!