I've had an EVGA 2080 since 2018. Over the last few months I've noticed lower performance than I would expect, so I started investigating.
 
In Superposition at 1080p Extreme I'm seeing a score of 5740 where ~7200 is expected.
 
The power limit adjustment bar is grayed out in both Precision X1 and Afterburner.
 
Using GPU-Z, I can see that my card is always running at PerfCap Idle, even under load. Core clocks never exceed 1515Mhz, memory clocks never exceed 7000Mhz, and voltage never exceeds 0.775V.
 
I've tried uninstalling and reinstalling drivers with DDU. Tested the PSU cables with a Dr. Power II - both tested at 12V. Tried reflashing the card's BIOS/firmware. Still stuck with the same issue.

evgoli
Are you using two individual PCI-E power cables from the PSU or one splitting into two?

Using two cables.

Make sure you aren't running both PX1 and AFB both at the same time.
 
I would also venture into doing a restore to the point where you saw your performance being optimal but before doing that as your last resort, also make sure your performance is set to max under the Nvidia CP.

GTXJackBauer
Make sure you aren't running both PX1 and AFB both at the same time.
 
I would also venture into doing a restore to the point where you saw your performance being optimal but before doing that as your last resort, also make sure your performance is set to max under the Nvidia CP.

I don't have both running. I've tried uninstalling one or both. Also have performance set to max in the Nvidia control panel.

evgoli
Have you checked in Afterburner settings that Unlock voltage etc. is done?
Tried using other versions of Afterburner?
Using latest motherboard bios?

I have updated my BIOS. Haven't tried different versions of Afterburner, but I have tried both Afterburner and Precision X1. Same issues with both. Problem seems to be with the card/driver/card firmware and not Afterburner.

Sajin
Time to rma.

I was afraid of that. It seems very similar to the issue Gamers Nexus experienced with their 2080. According to EVGA, Gamers Nexus was able to resolve with a firmware flash, but I have had no such luck.