Strange DX11 performance

[SpriggsyUK]

Hi, so I'm having some very strange DX11 performance with my 5080.
It's really far off what I'd expect from the card, and in games that support DX11 and DX12 I can see how big the difference is.
I've reinstalled drivers with DDU, attempted to reinstall DX11 (windows won't let me), done a windows refresh and a few other things.
So far nothing has changed, in the slowest 3Dmark Firestrike run it's had the 5080 is 28 - 39% slower in test 1 & 2 than my previous graphics card's best run.

Any ideas would be great at this point because this is really confusing, 3D mark comparison linked and Shadow of the Tomb Raider benchmarks attached.
https://www.3dmark.com/compare/fs/34012614/fs/29969658

[Mumintroll]

Have you tried an older driver version?

Do the same test with 581.80, or with the previous version you used before 581.94. 

[SpriggsyUK]

2 hours ago, Mumintroll said:

Have you tried an older driver version?

Do the same test with 581.80, or with the previous version you used before 581.94. 

Behaviour is the same, I rolled back to 576.28 to see how performance was.
https://www.3dmark.com/fs/33994483