Nvidia Software QA Manager Says Long-Awaited DPC Latency Fix Is Ready
After a little standard QA testing, the fix should be released.
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.
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.
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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.
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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...Reply
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 -
Diceman_2037 The fix won't be in drivers till R540, standard QA for KMD changes is 3-6 months.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
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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. -
The Historical Fidelity
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 talkingDiceman_2037 said:You'd have a point if it affected games at all. -
mta1124
wth? that fixed it for me.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 -
uncyler825
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.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 -
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