The capablity is there for 800W with the parts on the card. It would probably hit 600W no issues if there were no power limits.

The issue is hardware design.
Use a real load like a game, Then the GPU is getting vram, memory controller, int8, int16, int32, fp8 and fp16, rtx loads.
So using all different parts of the chip.
One of those is pulling power from the slot, Card hits slot power limit and wont go futher since it doesnt have digital vrm control like other brands do which would then direct more power from a input thats not on its power limit.

No XC3 is going to do 600W with out shunt modding it, PCI-Slot power bypass and replacing the fuses with jumpers.

They have fuses on them that will blow at 520W. I know this because thats where mine blew a plug fuse even tho the maths says it should do 550W before it blows one.
Im guessing your talking about frame chasers, His videos are for entertainment only nothing he provides is fact.
He gets called out on it all the time and just bans people that call him out instead of answering.
Which he did to me when he said his card was doing 650W on a stream and I told him about the fuses to which he replied his card doesnt have fuses so I posted screen shots from his video where you could see the fuses clearly on it.

bmgjet
No XC3 is going to do 600W with out shunt modding it, PCI-Slot power bypass and replacing the fuses with jumpers.

They have fuses on them that will blow at 520W. I know this because thats where mine blew a plug fuse even tho the maths says it should do 550W before it blows one.
Im guessing your talking about frame chasers, His videos are for entertainment only nothing he provides is fact.
He gets called out on it all the time and just bans people that call him out instead of answering.
Which he did to me when he said his card was doing 650W on a stream and I told him about the fuses to which he replied his card doesnt have fuses so I posted screen shots from his video where you could see the fuses clearly on it.

You miss the point entirely --- the point is that the card isn't physically limited to the 336w that they're allowing.  The standards alone allow for 375w using 2 8 pins and the bus.  This is the rated capability, not the components.  Yes the shunts are hard limiters for the 375w level, but not the 336 peak we're seeing under standard loads.  As for FC's claims, I don't take them as investing advice, I take them for what they are, a 3rd party making a claim -- which is ironically the same way I view your claim of burning a current limiting device at 520w.

halogenik
sorry to dig up a zombie thread but is there any way the 3080 xc3 hybrid cards can get a bios power update? I understand the stock cooler might not be up to snuff, but why sell a water cooling kit for a card if the power draw is going to be the same?

unfortunately it's the same bios for the XC3 Ultra. so the only thing the hybrids have over the air-cooled counterparts is quieter/lower operating temps. I was not able to OC my card with the hybrid install any more than on air. 
I also have not found a vbios that works to lift the 336w power limit for games. I've tried all the 2x8 pin vbios with nvflash. if anyone else has found something that works lmk. 

03whitegsr
EVGA not supporting an XOC bios on the XC3 makes sense in a normal market where you can buy which ever card you want. You pay extra for that extra support. It's pretty dumb though when just getting a card at all literally involves winning a lottery in some cases.

I sure would love a higher power limit as my card runs into the power limit around 925mV@2040MHz. ~400W would likely get it up to that 1080mV voltage limit and pick up ~8% more performance.

Are there third party bios editing options?

Nvidia encrypts the vbios now so you can no longer edit

This is why I sold my 3080 XC3 Hybrid. It was LITERALLY pointless to put a 240mm AIO on a card that power throttles @ anything over 1.00v.

I now have a 500 watt 3090 FTW3 Hybrid (with modded thermal pads but that's a whole different issue) that happily sits at 2115MHz @1.025v all day long running 52C on the core and 74C on the memory. So much better than the XC3 variants

For me, the constant fluctuating core clock coincides with micro stutter in some of the games I play. That's why I love the ability to set a specific core clock and forget about it.