Help with GPU + MOBO issue

[R3v07v3R]

Ok - I'm sorry if this is in the wrong place I don't use forums very often, but I've come up with a problem that I am completely baffled by, so here it is.

I know my system is old, I don't have any spare money at the moment...

 

My RIG:

MOBO: ASUS MAXIMUS IV GENE-Z

CPU: i5 3570k

RAM: 8GB mixed brands (slot1=8GB,slot2=4GB,slot3=empty,slot4=4GB)

GPU: R9 270x Gigabyte Windforce

Spare GPU: 9800GT

 

So here is the issue:

I was poking around in my BOIS to overclock my CPU (no issues there I got it to run @ 4.6GHz comfortably) and I found a reading that says my GPU is running at Native 4x or something, but it's supposed to be a 16x slot.  The motherboard has 2 x 16xPCIe slots.

 

If the R9 270x is in slot 1 (top slot) the BIOS says it is running at Native 4x

If the R9 270x is in slot 2 (bottom slot) the BIOS doesn't detect it

 

If the 9800GT is in slot 1 (top slot) the BIOS doesn't detect it

If the 9800GT is in slot 2 (bottom slot) the BIOS says it is running at Native 8x

 

(Another random test - Both Simultaneously)

The R9 270x is in slot 1 (top slot) the BIOS says it is running at Native 4x

The 9800GT is in slot 2 (bottom slot) the BIOS says it is running at Native 8x

 

There is an iGPU I can use for testing.

 

I can't understand this and unfortunately, the other motherboard I have doesn't seem to show me the PCIe's Native speed, as far as I can see, it's EXTREMELY OLD!

 

I wouldn't have too much of an issue with maybe running my R9 270x at 8x because I don't think it would make too much of a performance difference, but I have to assume 4x is considerably slower.

If anyone could enlighten me on that as well it would be appreciated.

[R3v07v3R]

no ideas at all?

[Krillingt75961]

Is the BIOS up to date?