100% CPU due to hardware interrupts?

Discussion in 'Windows Desktop Systems' started by lynchknot, Aug 8, 2006.

  1. lynchknot

    lynchknot Moderator

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    I too have high cpu but looking at my task manager told me nothing so I downloaded process explorer - However, I don't understand hardware interrupts and how to solve this problem. My mouse and keyboard become very sluggish until it stops - and that is often a very long time. This guy didn't seem to get anywhere but "reformat" - http://www.daniweb.com/techtalkforums/thread7297.html

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    Last edited: Aug 8, 2006
  2. kcnychief

    kcnychief █▄█ ▀█▄ █ Political User Folding Team

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    Actually your task manager tells you all you need to know, perhaps you didn't know how to interpret it?

    UTORRENT.EXE, TASKMGR.EXE, SVCHOST.EXE, SERVICES.EXE AND CHSERVICE.EXE are all using 20% of your CPU.

    UTORRENT especially can be a resource hog - are you using a Beta or a stable build. I would also recommend playing with your bandwidth settings, as that can change how agressive the app itself is.
     
  3. lynchknot

    lynchknot Moderator

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    If I shut down utorrent, taskmanager, chservice - other apps will take their place and I still will have 100% cpu. Systernals indicates it's actually hardware interrupts that is at a high level. Perhaps it has something to do with, "I just switched it back to DMA mode this morning and it has already reverted back to PIO mode this afternoon. I have Win XP sp2, and that thread suggests that it's most likely a hardware problem if its occuring post sp2"

    Here after several hours the interrupts stop. This screenshot is with all the same apps open

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    Last edited: Aug 8, 2006
  4. kcnychief

    kcnychief █▄█ ▀█▄ █ Political User Folding Team

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    Well that makes sense, that other applications take the place of ones you close.

    If an application wants to run, and it can't because there are no CPU cycles available, they will sit in queue of sorts and run when they can.

    The only real test would be to kill all running programs, at that point System Idle should be at 99%
     
  5. lynchknot

    lynchknot Moderator

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    Basically, you are telling me you don't know what hardware interrupts are and why systernals shows a 95% cpu draw via hardware interrupts and task manager shows it as a application draw?
     
  6. jimi_81

    jimi_81 Moderator Political User

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    :nervous: a guess says.. its the motherboard talking to the peripheral?
    wikipedia says:

    In computing, an interrupt is an asynchronous signal from hardware or software indicating the need for attention. A hardware interrupt causes the processor to save its state of execution via a context switch, and begins execution of an interrupt handler. Software interrupts are usually implemented as instructions in the instruction set, which cause a context switch to the interrupt handler similarly to a hardware interrupt. Interrupts are a commonly used technique for computer multitasking, especially in real-time computing. Such a system is said to be interrupt-driven.
     
  7. lynchknot

    lynchknot Moderator

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    I don't know. It's weird. For a while it's 100% then suddenly we are back down to 0% with all the same apps open - including Utorrent still actively up/downloading.
     
  8. kcnychief

    kcnychief █▄█ ▀█▄ █ Political User Folding Team

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    I do know what they are, I just have to take one on the chin and admit I only skimmed the previous post.

    I guess I would ask next as to what hardware changes, if any, you have made recently?
     
  9. lynchknot

    lynchknot Moderator

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    no changes.
     
  10. lynchknot

    lynchknot Moderator

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    Here's another instance that this happens. The second I start to unpack a winrar file, the hardware interrupts skyrocktet from a low % to high % but task manager will show sudden increase in CPU for some apps that were only using 0-2% cpu a second ago. Not just what you see in this screenshot but many apps that always stay at 2% or less are not jumping to 20%+- just because I opened winrar? ***edit - winrar is done, now all apps are back down to 0-2%. Interrupts back down to 2%

    [​IMG]
     
    Last edited: Aug 9, 2006
  11. jimi_81

    jimi_81 Moderator Political User

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    i remember once a guy having an issue where his ethernet card was getting on in age, and his system was running like crap because of it. we took it out and it worked just fine.

    the system's performance was restored.
     
  12. lynchknot

    lynchknot Moderator

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    It's running fine now. It seems to be limited to unpacking winrar and opening utorrent (had same issue with azerues) but once utorrent is open and CPU's finally drop down to normal, utorrent is no longer an issue while it's open. Starting these two apps is the issue as it seems these are the only two that provoke hardware interrupts.
     
  13. lynchknot

    lynchknot Moderator

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    I had some issue with connection so I just decided to True Image. When I did I lost my other partition information and it would not show that partition in "my computer". I decided to run Test Disk then Spinrite (because I did not think I used test disk correctly) long story short, I have no high "Hardware Interrupts" at all now. It was 95% while unpacking a rar file but now it's less than 5% unpacking.
     
  14. LeeJend

    LeeJend Moderator

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    If it's only happening on HD intensive tasks it sounds like the HD controller (or the HD itself) is having problems. If you don't have Smarts turned on in bios turn it on so the HD can do and report full diagnostics. Run the HD manufacturer's diagnostic program (after smarts is turned on).

    It could also be an IRQ assignment conflict. If you have an expansion cards installed swap slots. This will change the IRQ used.

    It's been a long time (decades) since I looked at the wintel device level architecture but from what I recall Windows maps almost all the hardware devices down into just a couple hardware interupts (as opposed to a polling system) using software interrupt requests IRQs. The keyboard might have had a hardware interrupt and the watchdog timer.

    The problem is all the devices eventually map into a "hardware interrupt" so anything could be misfiring and producing excessive requests for servicing. If you want to isolate it start pulling/disabling hardware one device at a time (sound, USB, CD/DVD, LAN, etc). It could be a MB problem too. An unterminated input on the interrupt controller could just be bouncing around causing false inteerupts. Something like a heavy disk access (rar, downloads, etc) could be causing higher noise levels and more false interrupts.

    Isolate what you can and if nothing removes the problem then the MB is suspect.
     
  15. X-Istence

    X-Istence * Political User

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    On my old laptop, with a PCMCIA Ethernet card, interrupts will max out the available CPU time especially when transferring at high speeds.

    It has to do with the fact that some hardware is firing an interrupt to get attention for something it has waiting/wants done. Do what LeeJend said, and see if you can find the problem hardware. Keep in mind that it could be something totally unrelated, like a keyboard or a mouse.
     
  16. lynchknot

    lynchknot Moderator

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    I'm not sure if you read my post correctly or maybe I wasn't clear but I do appreciate your response. Here is the condition under unpacking winrar now (no interrupt problem) when I did have the interrupts it would require over an hour to unpack a 700mb winrar file but now does it in 50 seconds!!!!!!: Also, I might add that I did recover that lost partition on the main drive with all data intact.

    [​IMG]

    But specs are really bad for a relatively new HD. From what I've been reading Seagate will spec badly to begin with so I don't know what to think. This HD had been in use since only June.



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    Last edited: Aug 23, 2006
  17. LordOfLA

    LordOfLA Godlike!

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    High interrupt levels using utorrent would indicate you've got more traffic to and from your pc than your nic can handle and it is then hammering the cpu. You'll need to reduce settings in utorrent related to transfers or buy a better nic (intel pro 1000mt for instance)

    From the hdd indicates a storage subsystem fault.
     
  18. lynchknot

    lynchknot Moderator

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    I don't have a separate network card. I run it off my MB: Abit NF7-S v2.0. The network adaptor is an NVIDIA nForce MCP Networking Controller.

    I have done nothing but run Test Disk and Spinrite - the interrupts are gone. However, I don't know what this is telling me. Perhaps it's not even related but just a coincidence.

    I'm not sure what you are referring to regarding, "hdd indicates a storage subsystem fault" do you meant the SMART results?
     
  19. lynchknot

    lynchknot Moderator

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    Perhaps I should add:

    ****edit - one more thing: I do quite a bit of large file transfers and deleting in my main drive second partion. I was seeing this error weeks prior to the interrupts. Upon (somehow) fixing the interrupt solved this issue as well. Unfortunately, this error has returned. As usual, the second attempt finds the folder

    [​IMG]
     
  20. lynchknot

    lynchknot Moderator

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    Well, no one at sysinternals would even respond to my post (100 views) - so they, apparently, don't even know. I appreciate those who have responded here and tried to come up with a cause. I'm guessing that the fact it has to do with unpacking a rar or downloading, it's something to do with I/O but then how could running Test Disk fix the problem?

    *edit - this thread received 624 views. There must be a relatively high degree of interest as it's a topic that is rarely covered.
     
    Last edited: Sep 4, 2006