1 Reply Latest reply on May 9, 2016 10:04 AM by omniphonix

    FirePro W4300 High DPC Latency Spikes Win10


      I recently purchased a FirePro W4300 for a DAW (Digital Audio Workstation) build after fighting DPC latency issues with an NVS 510 card. I just need a simple, multi-display card for 2D purposes with a driver that will not hang my CPU with DPC calls so I can get clean, low-latency, real-time audio. I had very bad issues with nvlddmkm.sys even on the very simple NVS 510 graphics card. The W4300 does not exhibit the same issues in atikmdag.sys or atikmpag.sys, BUT I am showing terrible latency spikes in dxgkrnl.sys. Since the atikm drivers do not appear to be doing anything, I have to assume all graphics handling is handed-off to the DirectX driver. If you can read the screen shot I attached (this is an interesting new finding as Alt+PrintScrn and the Snipping Tool both produce screen captures as shown), you will see that the dxgkrnl.sys is seeing spikes over 0.5ms of DPC latency. Typically, a pro audio workstation needs to have less than 0.1ms of DPC latency and down in the 0.05 range is optimal. I feel stuck between a rock and a hard place with no GPU vendor having functional drivers for a Windows 10 audio workstation. I feel like maybe I should have purchased a Windows 7 license for this build instead (do they even still sell those?). Any help offered would be greatly appreciated. Here are some of the tweaks I've made trying to nail down this issue...


      • Turned off all CPU power saving (C-states, P-states, T-states, Turbo, EIST)
      • Manually set BCLK to 100.0 and disabled SpreadSpectrum and Asus's Xeon TurboCharger
      • Set the CSM to disabled (no legacy devices)
      • Disabled virtualization extensions on the CPU
      • Used bcdedit to turn off dynamic ticks, use the system HPET (platform clock), and use the enhanced TSC sync policy
      • Set the High Performance power profile
      • Disable the onboard Intel NICs while testing and using audio software
      • Disabled Windows Defender, hibernation, UAC
      • Blocked all Win10 telemetry servers in hosts
      • Removed almost all the built-in appx packages via PowerShell
      • Disabled services per Black Viper's guide
      • Switch to my MOTU Ultralite MK3 USB audio interface (no change)


      Here is the build list...


      • Xeon E5-2687W v4 (single CPU populated)
      • Asus Z10PE-D8 WS
      • 32GB Kingston DDR4-2400 RDIMM (4x8GB)
      • FirePro W4300 (Sapphire-branded)
      • Samsung 950 Pro 512GB System SSD
      • Samsung 850 Evo 2TB Data SSD
      • Vantec UGT-FW210 1394a/b card (TI XIO2213b chip) -> to Steinberg MR816CSX Audio Interface
      • Several USB MIDI controllers and copy protection dongles, Access Virus TI, Roland VG-99 (testing with the last two disabled)
        • Re: FirePro W4300 High DPC Latency Spikes Win10

          I have determined that this issue is absolutely related to the video card. A return to my old Radeon 4850HD resolved the issue with audio dropouts. I also noticed while this card was installed, my onboard ASmedia USB3 controller was not showing up in Windows 10. The controller came back as soon as I switched back to the old Radeon card. I am returning the card, I don't have any more patience for troubleshooting. This card is not acceptable for installation in an Asus Z10PE-D8 WS motherboard.