Network usage causes high DPC Latency

Hey everyone,

Happy New Year :)

After about 24 hours of booting my computer, I have seen my DPC Latency spike tremendously. At first, I thought this was an issue with my network card (since disabling it would drop DPC Latency), so I bought a new card. The problem didn't go away, so I realized it was something else. High DPC Latency is a problem since it causes audio and video lag.

As I troubleshooted the issue, I have realized the spikes were caused from network activity. For example, when I am seeding [not necessarily uploading] many torrents or am loading a website, it shoots up.

See below for a before and after screenshot respectively.

Does anyone know what may cause this and how I could prevent it?

Thanks in advance for your help,
Dan

interesting tool, mine is mostly green with the odd yellow.

but my green is not stable and low, its hovering between 90 and 350, and I read others who consider 90 to be the max they expect. Some above 500 every 10-20 seconds as well.

brady said:

turn of the power management options through OS and bios

Can you expand upon this please?

You might also want to check to see if you have the "Standard Floppy Controller" enabled through your Device Manager, that seems to be causing DPC latency as well.

DPC latency issues can really mess up things like TV Tuners.

Usually the peaks are caused by mal-performing drivers, the question is that it's not easy to determine which ones - or even whether any virtual drivers could be guilty, I get my PC right up into the red and it causes dipixellation and blocky abhorrences in WMC...

It's been so far, totally insurmountable. I've grown so sick of it that I'm thinking of blowing a wad on a network TV tuner in lieu of what's in my system specs

brady said:

turn of the power management options through OS and bios & NIC (wireless and wired)

Onboard nic will cause lag but only through initialization
Power savings programs / settings will cause this as well.

Thanks for the response dude -

I have "High Performance" chosen under power options in win7 and have turned off all power management stuff in my BIOS. Do you know how to do this through the NIC?

I wonder if interrupt moderation available on good nic's helps dpc latency, I believe there is a link.

In terms of multimedia performance I get pop's in my sound but I believe this is down to bad windows 7 creative x-fi drivers rather than DPC latency as I get no spikes when they occur. Also I had alot of apps open when running the monitor, I really should have done it it after a reboot with nothing loaded.

Update: When I exit utorrent and restart it, DPC Latency goes back to manageable levels. I think that after about 24 hours of seeding 150 torrents the latency goes crazy. Does this make sense?

after 24 hours of seeding, I think anything could happen