DCPs & Interrupts causing high CPU usage

[Rhodry]

Hello,

I've been having an issue with my PC of late. I first noticed the issue one morning when I went to use my computer. Speedfan was reporting that the core CPU temp was 40c, abnormally high, normally around 24 - 28 c considering it was idling all night. The CPU usage monitor on Speedfan was showing approx. 25% CPU usage. CPU 0 0 - 3% and CPU 1 around 80%!! So I loaded up task manager to see what process was using the CPU, however, SYSTEM IDLE was at 99%.. So there was an unexplained CPU usage. This was very odd! So I did what I thought was the natural thing and re-started it, this solved the problem for a while.. but it came back again after general use (browsing, emails, office)

After a short Google session I found Sysinternals Process Explorer that identified the CPU usage as DCPs and Hardware Interrupts.

My initial thoughts was that I had a little mishap when I was blowing out my PC and replacing the thermal paste. I had only done that a day or so before. THEN I remembered (The reason why I'm posting here) is that I had just that previous night updated the forceware of my 6600GT.. It's getting on a little bit, so and I've been thinking of updating. Then I read reviews of the 8600GT...(which I'm sure is a marked improvement on mine but I can wait for the 8600GTS to come down in price eventually, I'm not in a great hurry).. so I thought maybe I'd try to OC. Something that I don't have very much experience with. I discovered that for me the easiest way would be to get the Coolbits add on for the NVIDIA CP and adjust the frequency's in there. So I slowly went from 500/800 to 590/855. During the increases I ran the performance test in F.E.A.R: This was my final result.

Stock 500/800:

Below 25 FPS 27%

Between 25 & 40 FPS 49%

Over 40 FPS 24%

OC 590/855:

Below 25 FPS 3%

Between 25 & 40 FPS 72%

Over 40 FPS 25%

Considering I've never done that before.. and I didn't spend any money.. I thought that was a pretty good result! Oh I don't have temps for you sorry.. I also played for an hour or so. I think you refer to them as "artifacts" they must be little glitches in the graphics or something.. well I didn't notice anything like that, so I guess I stopped increasing the frequency around the right spot.

So, back to DCPs & Interrupts. I selected to use the original frequencies and woo hoo!! A logical CPU usage.. just a very little flicker of the DCPs & Interrupts usage. 0.78 for both every 10 seconds or so. Instead of a reading of 10 - 20. I have no way of knowing if this was how it always was. But I always noticed that when idling the CPU usage flickered from 0 - 3 %, but of course that could have been any number of things.

So, I'd gotten somewhere. I'd found out (at least a component) what was causing the issue. But I rather liked the results of OC'ing my 6600GT and really didn't want to give up that easily. So after a lot of trial and error I found out that If I disabled my wireless network card (I know, probably the first thing I should have done with this issue) then with just my stock GPU speeds, Interrupts/sec dropped from an average of about 1100 to 500.. wow. Oh, I had discovered that all the information on DCPs and interrupts I needed was in the standard performance monitor in the control panel. I just needed to tell it to monitor them. I know for next time..

SO.. with this information I enabled my wireless card and noted that the interrupts/sec shot back up and leveled out around 1100 again. I then OC'd the graphics card again to 590/855, and the interrupts shot up to approx. 25,000!!.. hehe. SO.. disabled my wireless card (still OC'd) and it dropped straight back down to 500! Couldn't believe it! I just tried it on a whim.

I'm not really sure what to do with this information though. Just seems to be the combination of the wireless card and the OC'd 6600GT.. but the system is fine (well I think 1100 is within "fine") with either/or..just not both together. Do I try a new wireless card? Do I try a clean install? Any advice or similar experiences? And sorry this was so long! Just providing as much info as I can. Thanks!

System specs:

MOBO: MSI K8N Neo4-F (PCB 1.0)

CPU: AMD 4600+ 939

RAM: 2 GB (4*512) DDR 400

Video: Gigabyte GV-NX66T256DE 6600GT

Wireless NIC: Netgear WG311T 108 Mbps PCI (Note: Had to use Atheros drivers for 64-bit)

HDD: 250GB Seagate SATA & 320GB Seagate SATAII

Ext. HDD: WD 250GB Essentials.

T.V. Tuner: Twinhan PCI DTV

O.S. Windows XP Pro x64 SP2

To any moderators, I really wasn't too sure if this was the right place.. But it happened after overclocking..

[Rhodry]

Hi,

Well.. A clean install has solved the problem. I've ran every test I can think of to try and generate some sort of error or warning or something. But so far I've gotten nothing at all. Completely stable again. I assume some sort of driver issue, perhaps old drivers didn't get uninstalled properly, but only an issue with OC'd video card and wireless enabled..*shrugs*.. Anyone else had similar experience? Or know of some sort of test to check for a latent issue?

Cheers

[gyunter]

Well I have the same problem but still - no ideas how to solve it.

My config:

AMD 3500+, Gigabyte K8T890 MB, 2xHDD's with SATA interface and other stuff.