4 Replies Latest reply on Jul 31, 2015 2:52 PM by cfuser

    144Hz Fluctuating GPU Clock Speeds

    cfuser

      Hey there, I'm having this strange problem with my new configuration, which includes a 144Hz monitor.
      The clock speed of both GPU's are fluctuating in pretty much every 3D application. It can range anywhere from 750MHz - 1000MHz but only in 120Hz or 144Hz mode.

      In 60Hz mode the clocks are rock solid @ 1000MHz... I'm not sure if 3D and 2D clocks are conflicting or whatever but any help would be much appreciated.

       

       

       

      Cheers

       

      Setup:

      I7 3770K @ Stock clocks / undervolted stable
      Asus P8Z77 V LX MOBO
      Corsair vengeance 16GB 1600MHz RAM

      H80i closed loop water cooling for the CPU

      2 x Sapphire R9 290's Tri-X

      1TB Samsung HDD
      250GB Samsung EVO SSD
      RM1000 PSU

       

      Message was edited by: CF CF To include more detailed specs

        • Re: 144Hz Fluctuating GPU Clock Speeds
          Thanny

          Higher frame rate means higher load on the GPU.  Higher load means more power draw and higher temperature.  Both of those can cause the card to reduce the clock speed.

           

          What are your GPU temperatures when this happens?  What's your power limit set to?  What's your target temperature set to?

          1 of 1 people found this helpful
            • Re: 144Hz Fluctuating GPU Clock Speeds
              cfuser

              Indeed, I have it running with V-Sync off on both 60Hz settings and 144Hz.

              GPU temperatures vary depending on game. But GPU 1 usually never surpasses 82 degrees C, GPU 2 doesn't surpass 70 degrees C - Doubt it's throttling.

              I set the power limit to +20% before and it had no effect.

              Also this happens instantaneously, even with the cards @ lower temps the GPU clock fluctuates as soon as I boot up a game.

              • Re: 144Hz Fluctuating GPU Clock Speeds
                cfuser

                Ah so I think I've narrowed it down to a fullscreen problem. It worked perfectly until I alt-tabbed out and then back in. Then it started downclocking again in Far Cry 4.

                Never had this problem before. It sometimes works but for the majority it downclocks or hovers around 950-1000MHz. Also I noticed a slight flicker of the windows bar while in fullscreen. I'm really not sure what's going on here...

              • Re: 144Hz Fluctuating GPU Clock Speeds
                cfuser

                Answer:  Overlooked the fact that my second PCI-E bus was only rated for x4. Meaning I was running in 16x and 4x - The clocks adjusted accordingly

                Disabling Crossfire and running 3D Mark confirmed this

                Not even disappointed, problem has been routed (as nicely pointed out by a user on Hardware Canucks.)

                Solution: Getting a new MOBO