snadge

CONFIRMED THAT PROBLEM STILL PERSISTS IN WINDOWS 8 this is screenshot of DPC/IR using 13% of my dual-core CPU when downloading a file on Bit-Torrent at 1.6MB/s installed windows 8 fresh and using Atheros driver or MS 2011 driver is still the same. what will the trace tell you? ive done all that before and it said that NDIS.SYS was the culprit

yeah thanks for the help, really much appreciated for that. JUST WHEN I THOUGHT IT WAS GETTNG BETTER, ive done some testing and the DPC/IR CPU usage in resource monitor is still high, it seems to be erratic, I ran Latency Mon during this test copying files FROM usb drive to DESKTOP and downloading at full speed of 1.8MB/s the DPC/IR usage in resource monitor was 30% (avg of 22%), when the file copying finished and downloading was still going on the usage dropped to 10-15% - but - in Latency Monitor it showed no problems with DPC/IR ...so whats going on? how can there be no issues when RM shows as much as 25% of CPU power devoted to DPC/IR here is screenshot of Resource Monitor during file copying and downloading at 1.8MB/s: here is screenshot of Resource Monitor after the file copying finished (but still downloading at 1.8MB/s) here are results from latency mon: (1m50s) Do I have problems or not? the computer is definitely "sticky" when all this is going on

how do i do that? thanks edit: Highest DPC routine execution time (µs): 381 Responsible driver: ndis.sys (NDIS 6.20 driver, Microsoft Corporation) DPC count (execution time <500 µs): 3264015 DPC count (execution time 500-999 µs): 0 DPC count (execution time 1000-1999 µs): 0 DPC count (execution time 2000-3999 µs): 0 DPC count (execution time >=4000 µs): 0 # that was after 3 minutes of running...seems OK on there now but in RM the usage was still 5-15%

i tried it in XP once and the problem was gone... I had to install once on another partition to use the Netgear Flash Utility to flash my router which was corrupted from many fw upgrades, i thought I would test it and indeed the problem was gone I was told that DPC/IR process should NEVER used more than 1% CPU - is this true? I use latency mon which can tell me which driver causes it but its stays in the green most of the time, sometimes spiking in red with DPC/IR - but pagefaults get hit hard almost instantly and it says its latencymon causing it? svchost does too when i run a youtube video... eitherway I seem to get hit hard by pagefaults when using latencymon - I check DPC/IR usage in Resource Monitor which us built into windows (like an advanced task manager) just type resource monitor into startsearch and drag it to taskbar for shortcut - sort the process's list by CPU usage and start downloading files and moving files out to usb drive and watch the DPC/IR process hit the top of the list ... this is how I monitor it and test for it on machines, ive had a couple of windows 7 laptops in past (one of which i remember had atheros wifi driver) and they were the same... this problem is only noticeable by those 'tech' enough to realise something aint right... for me it was CPU usage in task manager was way higher than what totalled up in the processes window, thats how i found out, like i say i think its a bug in windows 7 and happens on most machines..either the users dont realise/notice or they have super powerfull CPU that can deal with it without affecting anything else (masking the problem).

thanks for speedy reply its an Acer Aspire 5051 windows 7 64-bit, 2Gb RAM (2x1 667Mhz), ATi Radeon XPres 1100 120Gb HDD Atheros AR5005G wifi adapter what is VHD BOOT? - I was actually gunna UPGRADE to it later on (aswell as test it for this problem) - I would bet money it still same on windows 8. I would prefer to install fresh but I have so much stuff installed.

Thanks for this, I used Xperf before in past and it was NDIS.SYS driver (windows 7 64x)... it is Atheros AR5005G wireless adapter running on latest versions for win7 it still does the same thing, I get this CPU usage when I copy files out to USB drive too - if I do both that and download files via wifi at 16Mbps then DPC/IR uses as much as 30 - 40% of my 1.8Ghz dual-core chip on laptop WIFI downloading at full speed = 10-15% DPC LAN downlaoding at full speed = 5% DPC Copying files to USB HDD - 10-15% DPC Both WIFI downloading at full speed and Copying files to USB HDD = 30-40% DPC EDIT: actually just checking it again (as its been a while) its nowhere near as bad as that now, for downloading on wifi its about 2-5% DPC/IR - but soon as I copy files to or from USB drive it spikes to 15% DPC/IR usage.. I wonder if its the wifi driver as ive been having problems with that too and been changing and trying different ones, the one i settled on was v 8.0.0.305 (Feb 2010) (I was having problems with speed peaks and troughs, latest v9 drivers just didnt work at all for uploading) - this driver seems to work best and ive tried all latest ones back over to this one. seems ATHEROS wireless drivers just do not like Windows 7 full stop. - I have seen and heard of this problem on other computers with Intel chipsets and other things causing the same problem. for me it seems to be a bug in windows 7.