My PCIe2 slot has "gone bad" and doesn't work

Hello, I've had my Z77 Extreme4 motherboard for a couple of years now (not really sure how long to be honest) and it recently didn't turn the monitor on when I started up my PC, so I changed the PCIe2 slot to the PCIe3 (which is only 8x). This has made gaming horrible, Witcher 3 is sometimes unplayable if I go into battle, it drops to the mid 20's in FPS. If I use Igni (a fire spell, for those that doesn't know) it also goes down to the 20's. This is super annoying and frustrating, 

KimaRo wrote: Hello, I've had my Z77 Extreme4 motherboard for a couple of years now (not really sure how long to be honest) and it recently didn't turn the monitor on when I started up my PC, so I changed the PCIe2 slot to the PCIe3 (which is only 8x). This has made gaming horrible, Witcher 3 is sometimes unplayable if I go into battle, it drops to the mid 20's in FPS. If I use Igni (a fire spell, for those that doesn't know) it also goes down to the 20's. This is super annoying and frustrating,  I've been watching my GPU usage while testing some games and it doesn't go at 100%. Usually it's around 60~% Here's an image on how it usually is. http://puu.sh/u2L1O/ea30735cbc.png The issue I've started running into is that whenever I use Steam Link, it drops my FPS insanely. Life is Strange doesn't go over 30fps. CS:GO is around 24FPS. Is there anything I can do? I've tried everything, I've disabled my iGPU. Also, when I check on my BIOS on what Gen i can use I have either Auto or Gen1. It should give me Gen3 aswell which is what it should be at (I just hope that Auto gives Gen3) Anyway, here's my specs:  i5 3570k @ 4Ghz (4.2 boost) 970 @ 1400Mhz Gainward Phantom 16GB @ 1866Mhz Corsair Platinum Dominator And all of my games are installed on my 2TB Seagate Barracuda. Some are installed into either my Samsung 840 SSD or my Intel 330 SSD

The drop in gaming performance you apparently have does not make sense. Since you have an Ivy Bridge i5-3570K CPU, you have PCIe 3.0 support for both of the PCIe x16 slots.

It is well known that the difference in performance between a PCIe 3.0 x8 and PCIe 3.0 x16 connection for a video card that is not driving a 4K monitor, will be very small, or no difference whatsoever. The worst case performance difference would be less than 5%, and that would be very unusual.

When you moved the video card to the other PCIe x16 slot, did you clear the BIOS/CMOS before you started the PC again? If you didn't, you really must do that any time you do a major change in the way hardware is connected to a mother board.

What BIOS version do you have in the board now?