DPC Latency

mike25907 said:

Hi,
My name is Mike. I have been having a problem for a few months and can't seem to fix it. In short, I'm a mobile DJ who uses a PC. I have 2 laptops. One is a Dell with Windows XP and the other is a Sony Vaio with Windows 7 (64 bit). The software program that I'm using works perfectly with my Dell but freezes when I use the Sony. Mike

Mike,

Thinking about this, I have some questions, will post tomorrow, it's way late here.

Ap

Mike,

I would think the freezing problem is separate from the yellow spikes you're seeing with the DPC latency checker. If the DPC latency is a little high, the most you will see/hear are occasional audio dropouts.

Besides, a few yellow spikes shouldn't cause a program to freeze in the manner you describe.

Possible problems:

-A background process is interferring with the program.
Reboot the computer, wait 5 minutes then open Task Manager (right click on task bar) enable "Show processes from all users". Select the Processes tab, resize the window to show all processes. Make a screen grab of the process window and post it here.


-Serato Itch is not fully Win-7/64-bit compatible, possibly having a problem related to accessing the full 4GB of RAM. (Although the tech says it is)

Does the Freezing occur if you select the Laptops built-in audio as the main output for Itch.

You're powering the VCI-300 with external power, correct?
I'm assuming you've tried all USB ports. Does the VCI-300 use it's own driver? Have you down loaded and installed the latest version?

Ap

Thanks so much for getting back to me. I'm sorry that it took me awhile to get back to you, things have been extremely busy on my end.

I haven't done what you recomended yet as far as grabbing a screen shot, but I will. If you don't mind, can you tell me how to grab a screen shot?

I AGREE WITH YOU 100% regarding your statement -
"-Serato Itch is not fully Win-7/64-bit compatible, possibly having a problem related to accessing the full 4GB of RAM. (Although the tech says it is)"

They will NOT admit to that. The constantly blame the freezing issue on the laptop, not the software. I've been reading & writing numerous threads on Serato's web site and noticed that there are ALOT of people are experiencing the SAME EXACT PROBLEM as me. Here is one response from the guys at Serato -

Sorry you are still experiencing issues. We'll continnue to keep helping you in your help thread, so keep an eye on that for the issue.


We have tested the operating system Windows 7 by Microsoft. The OS is compatible with ITCH.

However your laptop may be needing tweaks - laptop manufacturers can (and do) often ship computers loaded up with a lot of extras. Extras that can conflict with audio streaming. Some of your machine's drivers or hardware components may be setup by the manufacturer in a strange way - and sometimes this can result in audio issues. There can be many causes, but it's almost always the laptop setup.

We do love to find out any problems with ITCH however, so any bugs we can uncover we are certainly wanting to find as that will lead to better software

Like I said, I'm convinced that Windows 7 64 bit is NOT compatible with the Serato software. I just DJ'd a wedding this past Saturday and used my Dell laptop with XP and had no problems at all.



Thanks again for your assistance,

Mike

For screenshots. Type "Snipping Tool" into Windows search and hit enter.

A small window will open. Where the tab says New click the arrow and a list of options will appear. You can take window snips, or drag and highlight what you want to capture using rectangular snip. Have a bit of a play with it. You'll have it figured out in a few minutes.

Thanks for keeping us updated on the situation.

Hi Everybody. I had this issue and ran across a workaround (for me at least) on this website: MSE gradually increases DPC latency when there are high network activity My DPC latency has gone down from 117000 u-secs to an average of 170-250 u-secs. As it turned out Microsoft Security Essentials was unable to keep up with the task of real time monitoring of my uTorrent activity after about a day of being on. I hope this helps somebody. Good luck!

I've been suffering of DPC latency for a few months, after more than 1 year of using my machine with no problem at all.

I learn about DPC Latency, and figured out that my NIC was causing the the latency.

I upgraded my BIOS and the NIC driver, but nothing solved it.

Reading this forum, I read that the Microsoft Security Essentials might be causing the problems.

After just started the uninstall process, the latency droped from 11379 to a average of 130us.

Now I'm using AVG 2011 Free, and sometimes I get a pick of 4000us.

Gonna be monitoring this and get back to you guys in a few days.

I know this is a bit of a bump, but I thought I'd share my experience to help the ppl with latency spikes.
I was having these as well and was getting a bit annoyed by the skipping music (Foobar2K) even with a high buffer settings.
Turns out the CPU's power saving features that windows 7 applies (more advanced than XP does) adds latency. This happens especially in times the system's relatively idle/ under low load. As listening to music isn't a heavy task at all (3% CPU usage max in my case), Windows will let the CPU switch to a lower performance state. Switching back and forth from this state is what induces the spikes. The problem can be even worse when you're heavily overclocking and your system's stability depends on finely tuned settings (dynamically changing these doesn't bode well).

Short solution: Click Start --> Search for "Power Options" and open this control panel --> (on default "Balanced (recommended)" is selected) Choose "change plan settings" --> "Change advanced power settings" --> "Processor power management" --> "Minimum processor state" --> change setting to "100%"

No more DPC latency spikes! (at least in my case)

Don't worry, functions like EIST, Enhanced halt and throttling (by means of lowering the multiplier) still work. These mechanisms are integrated in most modern CPU's and these options can be turned on/off in the BIOS.

Hopefully some of you will find this solution works. I can imagine this issue is a big PITA for people working with music and audio equipment that require low latency, stutterfree and gapless playback...

Propheticus said:

I know this is a bit of a bump, but I thought I'd share my experience to help the ppl with latency spikes.
I was having these as well and was getting a bit annoyed by the skipping music (Foobar2K) even with a high buffer settings.
Turns out the CPU's power saving features that windows 7 applies (more advanced than XP does) adds latency. This happens especially in times the system's relatively idle/ under low load. As listening to music isn't a heavy task at all (3% CPU usage max in my case), Windows will let the CPU switch to a lower performance state. Switching back and forth from this state is what induces the spikes. The problem can be even worse when you're heavily overclocking and your system's stability depends on finely tuned settings (dynamically changing these doesn't bode well).

Short solution: Click Start --> Search for "Power Options" and open this control panel --> (on default "Balanced (recommended)" is selected) Choose "change plan settings" --> "Change advanced power settings" --> "Processor power management" --> "Minimum processor state" --> change setting to "100%"

No more DPC latency spikes! (at least in my case)

Don't worry, functions like EIST, Enhanced halt and throttling (by means of lowering the multiplier) still work. These mechanisms are integrated in most modern CPU's and these options can be turned on/off in the BIOS.

Hopefully some of you will find this solution works. I can imagine this issue is a big PITA for people working with music and audio equipment that require low latency, stutterfree and gapless playback...

Doesn't seem to help me at all. Only if I disable all P2P apps and services. Which sucks.

Thanks for suggestion though.

I was getting DCP spikes over 16K which caused my audio playback to drop or create a buzzing sound.
I tried the suggestion by Propheticus and set the minimum processor state to 100% in power options. Now I don't get spikes that high but I still got one over 13K. Still, a vast improvement.