Nvidia Software QA Manager Says Long-Awaited DPC Latency Fix Is Ready

Nvidia battles latency
(Image credit: Nvidia)

Nvidia is on the verge of releasing a fix for its ongoing driver DPC latency issues. In a Twitter post, Nvidia's software quality assurance spokesperson Manuel Guzman said a fix is ready. However, the update release still had to go through the standard QA testing procedure before distribution.

While Nvidia has gone to great lengths to minimize input latency and improve responsiveness with projects like Nvidia Reflex, users of its drivers have been suffering from DPC latency issues for several GPU generations.

Nvidia battles latency

(Image credit: Nvidia)

If you are blissfully unaware of DPC latency, it is system latency introduced by a Deferred Procedure Call (DPC) in Windows. DPCs were designed for high-priority tasks to defer required but lower-priority tasks for later execution. However, DPC buffers can get filled, resulting in stutters, skips, and similar glitches in video and audio. These jarring latency symptoms are highly undesirable in gaming, viewing videos, and creating or listening to music.

People who suspect they have DPC latency issues can download various tools to check and help minimize the issues. However, for a proper fix, you will want a device driver that has been coded to minimize excessive latencies in DPCs. If you have a laptop or pre-built PC, NotebookCheck maintains a list of systems and their tested DPC latencies - lower numbers are better.

According to Mr. Guzman, Nvidia has now reached a stage where it has fixed its driver DPC latency issues. Of course, the proof of the pudding is in the eating, and we shall see shortly when the fixed driver(s) arrive. As the Nvidia software QA spokesperson says, please "stay tuned."

GPU Monitoring Apps and Updating Nvidia Drivers

From Guzman's Twitter thread, where the DPC latency news emanated, there comes a solid recommendation to exit all your GPU monitoring apps before updating Nvidia drivers. The crux of this potential issue is that if you forget or neglect to follow this advice, "the GPU monitor utility may inadvertently set a lower power target resulting in lower performance."

Nvidia Gamers Using Windows 11

Mr. Guzman also recommends that Windows 11 users with Nvidia GPUs update to the latest version. Apparently, Microsoft's latest update addresses Timeout Detection and Recovery (TDR) errors which could otherwise interrupt gaming sessions.

Mark Tyson
News Editor

Mark Tyson is a news editor at Tom's Hardware. He enjoys covering the full breadth of PC tech; from business and semiconductor design to products approaching the edge of reason.

  • Amdlova
    That's great. With latecymon you can see the issues with Nvidia has on the system... some times the dpc is too high make system unstable. @JarredWaltonGPU can you make a review of this new driver?
    Reply
  • pdixon0
    It's already possible to fix the DPC latency, and has been possible for a few years...

    I haven't got the original link (my apologies to the originator)

    1.Openup Regedit and go to
    \HKEY_LOCAL_ MACHINE\SYSTEM\CurrentControlSet\Control\Video\*****\0000\
    The *'s will be random numbers . There will be a few of them, pick the "0000" folder with the most keys in it

    2.Create the 4 PowerMizer keys (these will all be DWORD)
    PerflevelSrc
    PowerMizerEnable
    PowerMizerLevel
    PowerMizerLevelAC

    3.Change the values (double click on them) to
    PerfleveISrc 3322
    PowerMizerEnable 0
    PowerMizerLevel 1
    PowerMizerLeveIAC 1
    Reply
  • Diceman_2037
    The fix won't be in drivers till R540, standard QA for KMD changes is 3-6 months.
    Reply
  • IamNotChatGpt
    Are they talking about this De Guzman?

    Reply
  • The Historical Fidelity
    Man what a double standard between Nvidia and AMD. AMD still gets **** for their old buggy drivers back in the day yet no one considers a years old and still active and debilitating gaming bug from Nvidia to be anything of merit…

    Reply
  • Diceman_2037
    The Historical Fidelity said:
    Man what a double standard between Nvidia and AMD. AMD still gets **** for their old buggy drivers back in the day yet no one considers a years old and still active and debilitating gaming bug from Nvidia to be anything of merit…


    You'd have a point if it affected games at all.
    Reply
  • The Historical Fidelity
    Diceman_2037 said:
    You'd have a point if it affected games at all.
    It did, thus it does…don’t get me wrong I’ve bought Nvidia from the 4400 ultra up to the 1080, so I’m not just an AMD fanboy talking
    Reply
  • mta1124
    pdixon0 said:
    It's already possible to fix the DPC latency, and has been possible for a few years...

    I haven't got the original link (my apologies to the originator)

    1.Openup Regedit and go to
    \HKEY_LOCAL_ MACHINE\SYSTEM\CurrentControlSet\Control\Video\*****\0000\
    The *'s will be random numbers . There will be a few of them, pick the "0000" folder with the most keys in it

    2.Create the 4 PowerMizer keys (these will all be DWORD)
    PerflevelSrc
    PowerMizerEnable
    PowerMizerLevel
    PowerMizerLevelAC

    3.Change the values (double click on them) to
    PerfleveISrc 3322
    PowerMizerEnable 0
    PowerMizerLevel 1
    PowerMizerLeveIAC 1
    wth? that fixed it for me.
    Reply
  • uncyler825
    pdixon0 said:
    It's already possible to fix the DPC latency, and has been possible for a few years...

    I haven't got the original link (my apologies to the originator)

    1.Openup Regedit and go to
    \HKEY_LOCAL_ MACHINE\SYSTEM\CurrentControlSet\Control\Video\*****\0000\
    The *'s will be random numbers . There will be a few of them, pick the "0000" folder with the most keys in it

    2.Create the 4 PowerMizer keys (these will all be DWORD)
    PerflevelSrc
    PowerMizerEnable
    PowerMizerLevel
    PowerMizerLevelAC

    3.Change the values (double click on them) to
    PerfleveISrc 3322
    PowerMizerEnable 0
    PowerMizerLevel 1
    PowerMizerLeveIAC 1
    This keys code has no effect on RTX 40 Series, It is not work. Don't talk nonsense. It's not fixed the DPC latency issues.
    Reply
  • mta1124
    uncyler825 said:
    This keys code has no effect on RTX 40 Series, It is not work. Don't talk nonsense. It's not fixed the DPC latency issues.

    chill. all I know is before the fix latencymon would only show my system was struggling, after I did the fix in regedit it's showing my system is suitable
    Reply