AnsweredAssumed Answered

rx 480(pci3.0) performance issues on pci2.0 motherboard?

Question asked by jgi on Mar 14, 2017
Latest reply on Apr 4, 2017 by jgi

Hi I bought a gaming pc from a company who put it together for me.

Specs: When I first bought it: 2x Radeon R9 390 8GB, msi 970 gaming, amd vishera fx-8350, 850W Cooler Master V850series, corsair hydro h100i, 32GB DDR3 RAM, 500GB SSD,                                                                         asus xonar DGX, windows 10 home

            Now: Since the 2x Radeon R9s broke it has 2x RX480s which are now broken as well they only lasted about a weak...


I've had performance issues since the beginning with the R9s, with the R9s ist wasn't so bad lower frame rates then expected but as long as I kept or reinstalled the oldest radeon drivers nothing really bad.

After about 6 months both the R9s were broken, I returned the pc as it was still under warranty and it came back with 2 RX 480s.

With the RX480s performance was horrible frame rates averaging at best 30fps with the worst drops to 7fps


Both the R9 and the RX480 need pci3.0 ports for best results but they should still be able to run on pci2.0 ports however this could result in a bottleneck because pci2.0 is slower, according to this post especially if you have multiple according to this post PCI Express 3.0 x16 graphic card on PCI Express 2.0 x16 slot? - [Solved] - Graphics Cards.


Is this maybe the source of all the performance issues I and probably some others have been experiencing, the fact that under a higher workload the RX480, R9 and other newer pci3.0 gpu are simply incompatible with older pci2.0 motherboards?

I certainly think so because my R9s performed better and lasted longer because their older design requires them to be connected with a cable which should reduce the workload on the pci ports, while the RX480s don't need to be connected plugging them to the motherboard and power supply should be enough, but only being connected with the motherboard will result on a higher workload on the pci ports so it seems logical that RX480 performed worse and lasted only a week vs 6months for the R9.


I hope someone could confirm if this is the cause of all of my problems and broken parts.

Or if you are experiencing similar issues and you also have 2 pci3.0 gpus on a pci2.0 motherboard you could check if it actually increases performance when you remove one of them, then we would be sure...