I just completed a new system build with a 3090 FTW3 Ultra, and I am trying to reconcile unexpectedly low TDP numbers in GPU-Z with the PerfCap Reason given as PWR (green). 
 
I am using the XOC 500W BIOS for this card, but the card never draws more than 435 or so watts, even under full load in Timespy/Timespy Extreme. My boost clocks are generally in the high 1800s/low 1900s, with brief spikes up to 2100 or so, so I'm not even sure this is really a problem, but with all of the reports of this card being extremely power hungry I am trying to reconcile that with the results I am seeing here.  It doesn't look like any of the temperatures or voltages are reaching problematic numbers, so I'm not sure how to interpret the "Pwr" reason for throttling when I would expect the GPU should be able to draw nearly 150w on each of the 8-pin connectors.  The "Power Consumption %" value also seems off with a max of 104% - shouldn't the TDP be 500w with this BIOS, meaning the TDP % should instead be 88% or so?
 
Here is my info and a screen capture of my GPU-Z results during timespy extreme:
 
Card:  EVGA RTX 3090 FTW3 Ultra (Purchased November 2020)
Bios: Latest XOC 500W BIOS - 94.02.42.80.27 (I've looked up the BIOS from GPU-Z and confirmed it has a target of 420w and a limit of 500w)
PrecisionX Settings: Power: 119 / GPU Temp 91 (slider maxxed to the right) - Overclock setting +200 core clock, +800 memory clock, +12 on voltage
I also updated the fan profile to be a bit more aggressive since it wasn't coming close to topping out.
 
GPU-Z Screen Capture:   (link, in case this is too small:  )
 
Hardware:
PSU: Corsair RM850X 850watt power supply
Motherboard: Asus Maximus Hero Z690 (BIOS 0811)
Processor: Intel 12900k (just using Asus board default settings, no other overclock)
Memory: 32GB Corsair Dominator DDR5 5200 (XMP profile settings)
 
Some theories:
 
1) Nothing is wrong?  I should just be happy the card isn't drawing more juice or crashing - and maybe this is all within normal operating parameters - it's not like it's crashing and it generally seems to be able to maintain boost clocks over 1800 mhz with no trouble.
 
2) The power supply isn't up to the task of running both a 12900k and 3090?  All of the recommendation engines I've used say 850 should be enough, and that the rm850x is a decent quality PSU, but maybe it's not enough here and that's limiting the amount of juice available for the GPU?
 
3) Something is wrong with the card and it isn't pulling as much power through the 8 pin connectors as it should?
 
4) I'm running in 3440x1440 resolution - is it possible I'm CPU bound at this resolution instead of GPU bound and the card doesn't need to clock any higher because it's limited by the CPU?  Seems unlikely since I have the same issues running Furmark as well, but maybe I'm not appreciating the interaction between components and power draw here.
 
I've followed the basic troubleshooting guide already and run DDU and reinstalled the drivers, and I've updated the BIOS to the 500W XOC BIOS as well.  Any thoughts or suggestions (or indications that this isn't a problem at all) would be appreciated.  Thanks!

Looks fine, if you want it to draw more power you can slide the voltage to 100 but that doesn't mean your score will increase. my KPE runs about 70w less than max power available on LN2 bios on most TS runs . 

PCIE slot power draw is over spec. This was discussed to death in https://forums.evga.com/EVGA-GeForce-RTX-3090-FTW3-XOC-BIOS-m3124192.aspx and affected the Rev 0.1 cards. The Rev 1.0 cards seem to be much better with a different voltage controller.
 
TLDR: ~67W max is what it should read, as properly functioning 3090s from other manufacturers read (75W is the max per the PCIE specification, but only the 12V input is read by GPU-Z, and not 12V + 3.3V - so, a reading of 81W is actually close to 90W, and so the card is limiting your overall power draw to the same as if you hadn't flashed the 500W VBIOS due to the high PCIE slot power draw).
 
You can flash a 3090 XC3 VBIOS, or the unlocked 3090 Kinpin VBIOS, to bypass that and get increased power draw (really not recommended for most people), or you can RMA the card per the second post in that link.