2 Replies Latest reply on Jan 12, 2016 1:19 AM by st7777

    Sapphire Nitro R9 380 4gb shows pcie 2.0 in pcie 3.0 slot

    st7777

      Hi there,

       

      my first time here so here's my 'problem'. I just installed a Sapphire Nitro R9 380 card in the pcie 3.0 slot of my Asus P8Z77-V LX motherboard. I noticed that in the Radeon settings hardware tab on the system page the bus type is PCI Express 3.0 but the current bus setting is PCI Express 2.0 x 16. I installed GPU-Z to double check, and it confirms that the bus runs at pcie 2.0 x 16. Interestingly it shows that the card throttles up from pcie 1.1 to pcie 2.0 under load.

       

      My question basically is, is this 'normal' or is there something in the system preventing the R9 380 from achieving pcie 3.0 performance?

       

      My system is as follows - MB: Asus P8Z77-V LX, CPU: Intel Core i7-3770 @ 3.4Ghz, RAM 8 GB Corsair Vengeance, PSU Thermaltake Toughpower 700W.

       

      Looking forward to hearing what you think, thanks in advance.

        • Re: Sapphire Nitro R9 380 4gb shows pcie 2.0 in pcie 3.0 slot
          amdmatt

          It's normal for the PCI-E lane to throttle back during idle loads. Are you using the first PCI-E slot? Is your system set to use a lower power profile? Check your Windows Control Panel > Power settings. I would recommend contacting the Motherboard manufacturer for further support on this matter.

            • Re: Sapphire Nitro R9 380 4gb shows pcie 2.0 in pcie 3.0 slot
              st7777

              Thanks for your advice - right on target. I had a look at the bios settings and tweaked a few settings that seemed relevant (disabled 'limit CPUID MAX', set Ai overclock to X.M.P. and enabled 'CPU turbo max'). I don't claim to understand exactly what those settings do but GPU-Z now indicates PCIE 3.0 under load, which is great. The only issue is that I've had a few crashes running Fallout 4 maxed out on ultra settings so I'm gradually reining in the BIOS - at present the system is running stable and Fallout 4 is looking great.

               

              Thanks again! Much appreciated.