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post #18 of (permalink) Old 07-11-2016, 11:55 PM
Dargonplay
 
Join Date: Oct 2012
Location: Florida
Posts: 1,490
Quote:
I just upgraded to a PNY GTX 1080 FE and unfortunately, even though the performance is great, all my games and videos on youtube or netflix now stutter sometimes with crackling sound.

As I already had some experience with crackling sound on an old configuration of mine, I decided to check the DPC Latency with DPCLat (I am on Windows 7 x64 SP1). To my surprise, I found out that the DPC Latency is around 350-400us when the PC is idle and it is around 900us with spikes up to 1500us when in game or netflix.
Quote:
OK we found a system we were able to reproduce this on. Thank you all for your assistance. Once I have further information I will update everyone.

You can check your DPC Latency with any of these two tools:

Latency Checker

Latency Checker doesn't work on anything past Windows 7, LatencyMon is recommended.

LatencyMon

This is a GTX 1080 @ load.



This is how it should look like:



For reference, here's a healthy 750Ti under max load with LatencyMon:



"Current measured interrupt to process latency" and "Highest Reported DPC Routine Execution Time" are the most important value with LatencyMon (LatencyMon is compatible with Windows 8/8.1/10)

"Current measured interrupt to process latency" is your current DPC latency in real time, "Highest Reported DPC Routine Execution Time" are your DPC spikes.

LatencyMon is intended to troubleshoot audio issues, such as crackling and dropping audio streams. Not GPU "stutter", but ideally your DPC readings should be as low as possible, under gaming loads anything below 50us is PERFECT, below 100us is AWESOME, below 200us is OK, above 200us is not OK, anything close and above 500us is a serious problem.

Your idle readings must stay below 20us at all times, ideally you should have less than 5us for "Current measured interrupt to process latency", you can basically ignore the Pagefault readings as these are just the amount of commands loading the RAM from your storage and OS drives.

Your load readingsmust stay below 50us at all times, ideally you should have less than 30us for "Current measured interrupt to process latency".

If your nvlddmkm.sys causes the high latency it means the Nvidia driver is the main source of DPC latency in your system, post in the Nvidia thread so they can find a solution, coming from a R9 290X to a GTX 1070 G1 I hope Nvidia fix this soon or I'll probably regret going green.

SOURCE

UPDATE 1:

A fix seems to be in the works.



Here's the knowledgeable user Cookieboyeli with great insight on what your target DPC latency should be and why.

Cookieboyeli's useful post.

UPDATE 2:

NVIDIA Display Driver Feedback is a survey born from this issue, I urge anyone with Pascal GPUs to check Cookieboyeli's post before using LatencyMon and then filling Nvidia's survey if you encounter any problems, it should help tremendously on the process of fixing this elusive bug which as many have said has been (to a lesser extent compared to Pascal) affecting several generations of Nvidia cards.

NVIDIA DISPLAY DRIVER FEEDBACK.

According to Manuel Guzman, NVIDIA's rep on Geforce.com forum :
Quote:
A fix will not make it in time for the next driver so it will likely be included as part of the following driver. If a fix is ready and validated much sooner I will push for a hotfix driver to get it out to everyone as soon as possible.
Quote:
It varies (DPS latency) by users configurations/drivers. If you see it on your system, swapping it for another 1080 card would give you the same DPC numbers. Our drivers are within Microsoft Windows specification for DPC but we are able to reduce it which should address this issue for users.

Hotfix driver now available to try.

http://nvidia.custhelp.com/app/answers/detail/a_id/4202
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