I was asked to post this here not the "Performance" forum for some reason so here goes, (again)...Hi -I don't understand why the DPC Latency of Windows 7 x64 is in the range of 125us where Windows XP SP3 gives <10us. Vista x64 SP1 and 2 are the same story.Disabling all devices - USB, on-board sound, DVD drives etc - but keeping only hard drives etc. enabled reduces the latency to 40us.Why so different?Makes using either Vista or Windows 7 are a audio workstation pretty intolerable.Ciao,Q.

Your not the only one :( XP was great for audio vista was a pig. I was hoping for good things in W7. I have found for me at least (I am on a laptop) it is the ACPI battery compliant driver that is at the root of it. Disable this in the device manager and it works fine but of cause you loose all the power feedback, not ideal at all.

Hi Q, After trying all the solutions mentioned on many forums (driver updates, disabling hardware devices, shutting down services, using legacy drivers etc....) I still had latency peaks of 5000 microseconds. Then I went to Control Panel --> Energy management and there I choose "Optimize for high performance" (I have the Dutch version of Win7 so maybe it has a diffrent name) And all the peaks were gone! They're still a little higher then in XP (as TS says) but they stay in the green. I hope this helpes for all people facing this problem. W.

I don't know how to thank you for this answer! I had the same problem with windows 7 but I hadn't tried any other os so I thought that it was a hardware problem and I was ready to change pc because I was running an important audio project that required no latency and drop outs....I searched a lot of forums but none of the answers suited to my case...till I found yours. Thanks a lot Wojah!

Hi, make a xperf trace [1] to diagnostic the DPC issues. Please upload the etl file to your SkyDrive [2] and post a link here. I'll take a look at it. André [1] http://www.msfn.org/board/index.php?showtopic=140263 [2] http://social.technet.microsoft.com/Forums/en-US/w7itproui/thread/4fc10639-02db-4665-993a-08d865088d65"A programmer is just a tool which converts caffeine into code" CLIP- Stellvertreter http://www.winvistaside.de/

I have a similar problem. Windows 7 Professional, I7 860, ASUStek MB (P7H57D-V EVO). Realtek PCie network adapter. DPC starts out fine and gets progressively worse over a day or two. Rebooting fixes it. There are hundreds of similar posts scattered around the net.People have tried different network cards and nothing fixes it. Sure seems to be a Windows 7 problem, and the fact that it deteriorates over time must be significant. The problem according to xperf is ndis.sys (maximum duration 6.3 ms). I'm not using a wireless card. Any suggestions? Thanks, Peter

The problem according to xperf is ndis.sys (maximum duration 6.3 ms). I'm not using a wireless card. Any suggestions? update all network related drivers/programs."A programmer is just a tool which converts caffeine into code" CLIP- Stellvertreter http://www.winvistaside.de/