dxgkrnl.sys High Latency

Geoff AB6BT

Using Lanency Monitor I see that dxgkrnl.sys has very high latency; it is currently showing 36338 uS.

Any suggestions out there to improve this?

Thanks!

Trucker

https://www.google.com/amp/s/www.partitionwizard.com/disk-recovery/dxgkrnl-sys.html%3famp

Geoff AB6BT

Hey Trucker,

I'm not getting the BSOD. I'm looking for a resolution to having to restart DAX frequently and several sources mention high latency as a possible cause. In your experience do any of these steps help with that problem?

Trucker

Run LatencyMon without DAX running. If the same high usage message appears, it isn't DAX itself causing your problem.

I had latency problems with a Flex 5000A and I used LatencyMon to help track down the problem. There are several things that can cause high latency. Processes running in the background are the main culprit. Dxgkrnl.sys is a Windows system file not a part of SmartSDR and DAX. I looked it up and that is why I provided the above link. You can also run Task Manager and see which applications are using a lot of resources. ( do it with SmartSDR running)

But, the first thing to do is run LatencyMon without SmartSDR and DAX running. That will give you a better idea as to whether or not, the problem is related to that system file or not.

James

AKA: Trucker

WD5GWY

Trucker

Geoff, check this link.

https://community.flexradio.com/discussion/8025321/smartsdr-installations-on-windows-11#latest

Geoff AB6BT

OK, good advice. I understand that the sys file is a WIndows system file. I believe I did have SSDR (and DAX) running when I ran LatencyMon. Since dxgkrnl.sys is the DIrerctX Graphics Kernel, I'm not clear what its effect is on DAX but It is probably related to the SSDR display.

I'll run the monitor without SSDR and associated bits running.

Geoff AB6BT

In about 45 minutes of running LatencyMon without SSDR or DAX the dxgkrnl.sys  latency is reported as 42,160 uS.

Trucker

You may need to update your video drivers. You probably should open a Help Desk ticket in case this is a conflict between DAX and your video driver causing problems. They can give you a set of instructions to follow to try and pinpoint where the problem is

James

WD5GWY

Geoff AB6BT

Thanks James!

Ron Koenig

After letting LatencyMon run several times on a very capable PC it would stay good for hours... But when left unattended I often came back with it displaying that it was not suitable for real-time Audio.

After much playing and research I kept coming back to CPU Throttling. There are several ways to change it, Bios, Registry etc. but this less invasive method, so far has had very promising results and lowered the long term numbers across the board.

Ron, WV4P

Geoff AB6BT

Hi Ron,

Yes, I've previously looked at the CPU throttling problem. I have had my power plan set to "High Performance" for a long time.

My experience is the same as yous. LM shows OK over the short term, but I just checked after it has been running overnight, and I see the warning message.

My experience with LM is limited and I'm not sure how to interpret the results as shown on th main page.

There is a bar graph, second from the top I believe, "Highest measured interrupt to process latency" That shows 5327 uS and that one is far to the right and into the red.

Below that are two graphics related bar graphs, one for DirectX anf the other for Nvidia, that show "Highert reported ISR execution time". These are 225 uS and 762 uS respetively. These are both green.

Now I need to figure what caused the "Highest measured interrupt to process latency" to be so high.

So little time and so much to learn...

Erik Carling EI4KF

You can run the DirectX Diagnostic Tool to check that your computer has upgraded to DirectX 12. It will also give you detailed information about DX and other drivers. For example:

The System tab will show which version of DX you are using. You never know you might identify a cause of the issue - worth trying if only to eliminate all the drivers it checks.

Invoke the tool with dxdiag in the Run dialogue box

Geoff AB6BT

Hi Erik,

I did run dxdiag. I'm not sure where to view the DIrectX version.

Direct3d DDI shows 12

But, Feature Levels shows latest as 11_0

Geoff AB6BT

THe main dxdiag tab shows DIrectX 12 is installed.

I'm not 100% sure any of this is the cause of the DAX corruption problem.

Seems like a rabbit hole...

Erik Carling EI4KF

If it all checks out then I concur - none of this has any bearing on the problem. What about computer resources? How up to date is the computer and how good is its specification? My experience is that it is processes running and tasks being done concurrently with running SmartSDR that cause latency and errors in DAX.

Geoff AB6BT

It's an i5-4590 3.3 GHz with 16GB Ram. Often run SliceMaster, FRStack, WSJT-X.

It can be difficult to track down as the LM warning message takes hours.

The DAX issue usually takes hours or overnight to occur. Usually fixed by restarting DAX.

Yesterday I tried starting one application at a time and waiting a couple hours with no clear cause and effect. I'll try again to test with a more systematic approach.

For now it may be more effective to just restart DAX although it bugs me to not find a resolution.

Geoff AB6BT

On the main dxdiag page it does show DirectX 12 is installed.

I'm not 100% convinced that any of this is the cause of the DAX corruption problem.

Geoff AB6BT

On the main dxdiag page it does show DirectX 12 is installed.

I'm not 100% convinced that any of this is the cause of the DAX corruption problem.

Larry _ NY8T

I have spent alot of time trying to trace why DAX corrupts and I think I figured it out. For those that also are having this issue, see if you have any DAX channels turned on in DAX Control panel that are not curently assigned to a slice, if so turn them off. Owning a 6700 I can turn on the 7 unasssigned DAX Channels and within a couple WSJT-x decode cycles it will go into corruption, then I can turn the unassigned channels off and it is back to normal without restarting DAX. If I Only have say one unassigned DAX Channel turned on, it takes longer for the corruption to happen, but as soon as I turn that unassigned DAX Channel off it corrects itself without having to restart DAX. Try it and see what you get.

Geoff AB6BT

Hey Larry--Yet another approach! I'll check it out later today.

David Decoons, wo2x

Geoff,

Is your computer using Intel Iris graphics? There was an issue where a new driver for the graphics card on the motherboard resolved it.

just a suggestion.

Dave wo2x

Geoff AB6BT

Hi Dave,

No I'm using an Nvidia card with the most current driver.