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Possible MB problem, high DPC latency and CPU load %

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  • Motherboards
Last response: in Motherboards
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September 7, 2010 3:32:14 PM

Hello,

I've experiencing for the last 3 months a problem that drives me crazy, I cannot seem to find any solution. My PC:

- Intel Core2 Quad 9300 @ 2.50GHz
- 2x OCZ DDR3 @1333 (before: 2x Kingston DDR2 1GB @800)
- AsRock 1600P35 WiFi+ (http://www.asrock.com/mb/overview.asp?Model=4Core1600P3...)
- Gigabyte GTX 275 (before: Nvidia 9800GT & ATI 4650 chip based graphics cards)
- 320GB WD HDD @7200
- Thermaltake 750W

In the meanwhile I have switched (or have been running simultaneously) 4 O/S (XP Prf 64b, Vista Ultimate 32b & 64b, 7 Ultimate 32b). The problem is the following:

While running in Windows environment (surfing with Mozilla, etc.) or playing a game (anything from PES10 to Fallout3), the PC seems to get into a CPU slowdown, it gets stuck multiple times per second (5+ per sec), so that everything goes slower and with bumps. It seems the CPU load is over 80% while the sum

of the values from the CPU flag
from all the current processes is at most 15%.

However, apart from that everything keeps running normally, the HDD does not seem to load anything, and I usually solve the problem by opening the task manager and closing the application I was running (f.e. the game or mozilla). The applications is responding normally even before I close it, ofcourse not running smoothly.

If this happens for 3-4 times per day, on the 5th time this happens or so I usually have to wait for 3-5 minutes after I've closed the application, for the system to "cool down" (??) and run smoothly again.

The problem appeared with all the different hw (RAM, graphics card) above. I tried to check DPC latency with DPC Latency Checker, and I get the following:

- When running heavy apps (f.e. CUDA apps) i get some 16.000+ μs bars every 6 secs. The application is running smoothly at the time.
- When the problem stated above appears (even if surfing in Mozilla, or running a game) I get constant 16.000+ μs bars, until the PC runs smoohtly again.

Can anyone please help on this one?

P.S. My MB is also running with high temperatures, after the system experiences the above problem I have restarted and checked temperature through BIOS, and it goes up to 120F (usually aroun 114F). Is this normal?

More about : problem high dpc latency cpu load

September 7, 2010 10:01:05 PM

loco2k5 said:
I tried to check DPC latency with DPC Latency Checker, and I get the following:

- When running heavy apps (f.e. CUDA apps) i get some 16.000+ μs bars every 6 secs. The application is running smoothly at the time.
- When the problem stated above appears (even if surfing in Mozilla, or running a game) I get constant 16.000+ μs bars, until the PC runs smoohtly again.



I also installed Process Explorer to check again.

During the CPU Slowdown mentioned above, the Interrupts peak up to 25%-30%, while when the system runs smoothly the % does not go above 3%, and this is just for msecs.

Process Explorer manual states:
On Windows NT-based systems Process Explorer shows two artificial processes: Interrupts and DPCs. These processes reflect the amount of time the system spends servicing hardware interrupts and Deferred Procedure Calls (DPCs), respectively. High CPU consumption by these activities can indicate a hardware problem or device driver bug. To see the total number of interrupts and DPCs executed since the system booted add the Context Switch column. Another sometimes useful metric is the number of interrupts and DPCs generated per refresh interval, which you see when you add the CSwitches Delta column.

Another point: I didn't get any CPU slowdown while using Ubuntu (surfing, listening to music, other stuff simultaneously), and I have used it pretty much now. Could this mean that I can narrow my problem to a driver issue or hdd issue?

Thanks in advance


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October 6, 2010 5:16:12 PM

Try this - uninstall any display adapter utilities.
I have a new HP 8540W. clean installed W7 Ultimate and drivers.
Serious latency - was OK the first time I did it. Difference??? I installed new NVidia drivers from NV site - not the old HP ones.

I uninstalled the nVidia utility and latency is averaging 100us with 10% at 745us. There was a few yellows at 1336us at the start.

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