KVR Audio

Resplendence · Post by **Resplendence** » Sun Sep 12, 2010 7:48 pm

http://www.resplendence.com/latencymon

Hi, this software was announced before had some rough edges and shortcomings, now fixed and ready to go live.

LatencyMon checks if a system running Windows is suitable for processing real-time audio by measuring DPC and ISR execution times as well as hard pagefaults. It will provide a comprehensible report and find the kernel modules and processes responsible for causing audio latencies which result in drop outs. It also provides the functionality of an ISR monitor, DPC monitor and a hard pagefault monitor.

It relies on the same technology that XPERF uses but is specifically tailored to check the suitability of a system for real-time audio processing.

For free but only supports Windows Vista or higher. Any comments are welcome (constructive or otherwise).

//Daniel

sounddesigner · Post by **sounddesigner** » Sun Sep 12, 2010 9:15 pm

Looks like a good app. I'll definitely download and give it a try. Thanks for the freebie!

UltraJv · Post by **UltraJv** » Mon Sep 13, 2010 12:49 am

Unless Im doing something wrong, there seems to be a bug - the main window has a scroll bar but I cant scroll down to see what else is there. It simply jumps up again. Resizing to full size eliminates the issue.

Stupid American Pig · Mon Sep 13, 2010 12:51 am

yeah I can verify that, it looks like every update resets the scroll bar position, so its not possible to scroll until you stop monitoring...

Resplendence · Post by **Resplendence** » Mon Sep 13, 2010 8:04 am

Thanks guys, it has been fixed as well as two other small problems.
//Daniel

Kaine · Post by **Kaine** » Mon Sep 13, 2010 10:42 am

I'm amazed no one's done something like this sooner. Good work, looks great.

speccyteccy · Post by **speccyteccy** » Mon Sep 13, 2010 1:15 pm

This is really useful - thanks.

I just wish there was some software that worked as follows:

Boot to safe mode, take a snapshot (1) of what drivers, services & startup items are loaded.
Boot normally, take a similar snapshot (2)
Allow the user to create a new profile (3) based on 1 with user-selectable elements from 2 (i.e. soundcard drivers)
User can then boot into profile 2 for normal use or profile 3 for audio use.

Resplendence · Post by **Resplendence** » Mon Sep 13, 2010 1:42 pm

I'm amazed no one's done something like this sooner. Good work, looks great.

"Better never than late" is the philosophy for audio buffers which are not delivered in time, hope that doesn't count for this tool. From Windows Vista this information is collected for us through ETW tracing, previous versions of Windows would require hacking away into the kernel making this very hard if not impossible.

I just wish there was some software that worked as follows:
Boot to safe mode, take a snapshot (1) of what drivers, services & startup items are loaded. ....

Yes, HW profiles were a great feature, it's a pain that they are gone. You might be able to disable devices on the fly with a Powershell script. Installing another copy of Windows on a separate partition is possibly easiest.

//Daniel

ermi · Post by **ermi** » Mon Sep 13, 2010 5:19 pm

Good stuff, thanks! I got an error after running it for 10 minutes, tho:

(with it closed, Task Manager reports 1100MB available and 800MB free memory)

How long is it supposed to run?

Also, any chance of it being available as "portable", without requiring an installation?

Resplendence · Post by **Resplendence** » Mon Sep 13, 2010 5:47 pm

ermi wrote:Good stuff, thanks! I got an error after running it for 10 minutes, tho: (with it closed, Task Manager reports 1100MB available and 800MB free memory)

Admitted, the software consumes quite a bit of memory. This is in part due to the design of ETW tracing. If I get more of these out of memory reports, I will consider reducing the buffer sizes and the amount of buffers. What OS is this and how much RAM do you have installed ? I would say leave it running for a while but not more than several minutes. If you want to investigate pagefaults you should run your audio application with the monitor running.

Also, any chance of it being available as "portable", without requiring an installation?

The software is portable, the installer is only supplied for convenience. You can put the files on a flash drive or network share and run it on another system without installation.

//Daniel

rifftrax · Post by **rifftrax** » Mon Sep 13, 2010 5:50 pm

That's a pretty awesome idea really.

Kaine · Post by **Kaine** » Tue Sep 14, 2010 8:55 am

Resplendence wrote: "Better never than late" is the philosophy for audio buffers which are not delivered in time, hope that doesn't count for this tool. From Windows Vista this information is collected for us through ETW tracing, previous versions of Windows would require hacking away into the kernel making this very hard if not impossible.

Ahhh, that would indeed explain why then. I gave it a run last night on one of my own builds that's been getting the odd crackle which I was having trouble nailing down. No DPC problem as I'd already worked out but your page fault read out showed me a problem with the harddrive which I hadn't even thought of that as being a potential issue seeing as it's fresh from the factory.

Once again, great stuff. Thanks!

Resplendence · Post by **Resplendence** » Sun Oct 03, 2010 9:22 am

I have updated LatencyMon to v2.00. Because of the memory consumption of the monitor in v 1.00, it did not give an objective overview of hard pagefaults as it was very good at provoking them. Now the monitor is switched off by default but it does display pagefaults per process and DPCs and ISRs and highest execution time per driver. This means you can now keep it running for long periods without any problems.
//Daniel

DevonB · Post by **DevonB** » Sun Oct 03, 2010 10:17 am

Nice indeed. Need to check this out.

Devon

UltraJv · Post by **UltraJv** » Sun Oct 03, 2010 10:35 am

The hard page fault count is off the scale here due to Latencymon. Its very misleading IMHO. Perhaps it should be left off?

LatencyMon: finding the root cause of audio dropouts, clicks and pops