Massive performance decrease after bios flash

You know how it goes. I browsed for awhile but couldn't find anyone with the same problems.

Long story short, I flashed a modded bios and my numbers are simply all over the place. At this point I'm just looking for any outside the box troubleshooting I haven't thought of. Here's a summary of so far.

Originally my Gtx 670 would pull a high 9000 or so score in 3d mark 11. Graphics being between a 10200 and a 10500. With about a +72 on the boost clock. I'm planning to put it under water so the plan was mod the bios, get the voltage to max and see what she can really do.

This of course, has failed. Miserably.

Modded my own bios. Flashed to new one. Reinstalled precision X. Rebooted. Highest I can get is 8500 score in Mark 11, and any change to the clock is a driver crash.

Tried another FTW bios. Same result, only worse. 7000 score. Temps are maxing at 50C. Tried a driver rollback. No help.

Back onoriginal Bios with Original Driver. Barely getting 9000. Second run right after resulted in a 7500 score. Original Bios.

At my wits end here guys, help me out. Any suggestions? Are EVGA 670 FTW Sig 2 cards weird?. Do I have to flash something specific? Am I missing a crucial step? Seems everyone else who doesthis stuff ddoesn't run into nearly the problems I do.

Help me out. I'm game for anything at this point.