Problem with PCI Express slot

[Str8Gell]

Hi, i have old mainboard "m4a89gtd pro usb3" when i got it didn't came with that PCI Express vga dummy switch card or what ever is called.

So at the moment my graphic card "r9 280x toxic" is working x8 instead of x16. I was reading the forums and saw that with that setup im having slight impact on gpu performance.

My question is, do i really have to have that vga switch card or i can somehow make it work without it?

 

[clutchc]

What is this "switch card"? I don't see any reason the first (white) PCIe x16 slot should not work at x16 lanes all the time. Are you sharing PCIe lanes with another device?
It used to be in those days that using a bridge for the 2nd card would cause the slots to share lanes @ X8 apiece. But that board has a 2nd slot at a "hard-wired" x4 lanes.

Either way, I really don't think a R9-280X is going to saturate the PCIe version 2.0 buss @ x8 lanes.

 

[Str8Gell]

Hi cultach

This is switch card:

This is the benchmark i was referring to:

https://www.techpowerup.com/reviews/Intel/Ivy_Bridge_PCI-Express_Scaling/23.html]

I have only one graphic card on my computer and i disabled the integrated one in bios.

 

[pete_101]

Gee, haven't heard of these things in years. Back when PCIe was quite new, it was common for some motherboards to split the lanes into 8x for each 16x slot. So, if you wanted a true 16x to the top slot you'd use one of these switch cards in the 2nd 16x slot to terminate feed to that slot which would feed 16x to the top slot.

So to answer your original question, as far as I know there is no other way to get 16x except by using a switch card. Looking at the chart, there is a 2-4% difference in performance, this isn't really enough to be too concerned about.

 

[clutchc]

Hi cultach

This is switch card:

This is the benchmark i was referring to:

https://www.techpowerup.com/reviews/Intel/Ivy_Bridge_PCI-Express_Scaling/23.html]

I have only one graphic card on my computer and i disabled the integrated one in bios.

Now I remember. Yes, Asus had that for some of their early boards. I had an Intel board from that era that used one of those in a special slot between the PCIe x16 slots. Insert it one way; it provided x8, x8 lanes. Insert it the other way it provided x16, x4 lanes I believe. Been a long time.

I presume you are using the graph's results for the HD-7970 as a close approximation to your R9-280X? If so remember, the graph refers to PCIe version 3.0. Your system is only 2.0. There may be a bit more loss at 2.0, but not enouhg to be concerned about.

If I read the manual correctly, the blue slot is @ x16 lanes using a single card. Have you tried that and benchmarked any?

Also, you might try Asus for a replacement.
https://icr-am.asus.com/webchat/icr.html?rootTreeId=AM.US.EN-US&treeId=AM.US.EN-US.MotherBoard&tenantId=EN-US&_ga=2.107267591.480147491.1525381289-1866406486.1525381289