CPU Always working too hard

By magsker ยท 6 replies
Jun 3, 2006
  1. It seems that my CPU is always working way too hard. I have a pentium 4 2.8ghz with a gig of ram. But for some reason I cannot run firefox, aim and itunes at the same time. itunes tends to freeze up all the time by hogging all of my CPU. Video is right out. There is no chance of video playing without completly freezing.

    I have AVG 7.1 with firewall, spybot, adaware, as well as the wintask 5 bundle and cannot seem to find a virus, worm, malware, spyware, or anything funny in my registry. What could possibly be wrong?


  2. ZeroCount

    ZeroCount TS Rookie Posts: 48

    Like most people, you probably don't think about how hard your CPU is working until you suspect that it's working too hard or not quite hard enough. As long as a system is up-and-running and giving the expected results, whether or not it's working efficiently isn't an issue. Only when someone's sitting waiting for a prompt, waiting for a process to complete, or noticing that the system isn't processing data as quickly as needed do you start to wonder what might be causing the slowdown. Is the CPU bogged down by too much work or are processes waiting for resources they need to run?

    To determine whether the CPU is responsible for a slowdown, you want to look at how the CPU is spending its time. Several commands will report on the amount of time the CPU spends in each of a number of states. The rightmost columns in vmstat output will show you something like this:

    us sy id 10 1 89

    In this sample output, the CPU is idle 89% of the time while it's spending 10% of its time on user processes and 1% on system calls. This output is quite different from this:

    us sy id 58 41 0

    Here, the CPU is spending all of its time processing (58% on user processes and 41% system). But how do we know whether the CPU is stressed or simply keeping up with the demand?

    One of the best indicators of a stressed CPU is the load average. This value indicates the average number of processes that are ready to run, but are waiting for access to a busy CPU. A CPU that's 100% busy but has no processes waiting represents an entirely different situation than a CPU that is 100% busy and has a load average of 10.

    One way to see the load average on your system is to use the top command (available as an add-on if you're using Solaris and included in Red Hat Linux). Solaris 8 users can use prstat and get a lot of the same information. In each case, load averages are reported as a series of three numbers representing the averages over the previous minute, previous five minutes, and previous fifteen minutes. It's no coincidence that the different commands report the same numbers; this information is maintained in kernel counters that the various commands query.

    The top command will report load averages on the top line of the display and will look like this:

    5:17pm up 3:16, 3 users, load average: 0.01, 0.03, 0.07

    If this output looks familiar, try comparing it with the output of the uptime command. Yes, this is the same data. We see that the particular system on which this command was run has only been up three hours and sixteen minutes and that three users are logged in (actually it's one user with three terminal connections). We also see that the load averages are extremely small and that the load appears to be going down -- i.e., the fifteen-minute average is seven times the one-minute average.

    The top command also goes on to give us some additional information. Here are the following two lines:

    68 processes: 67 sleeping, 1 running, 0 zombie, 0 stopped CPU states: 12.2% user, 1.6% system, 0.0% nice, 86.1% idle

    These lines tells us that 67 of the 68 running processes are sleeping -- waiting for an event of some kind to complete -- while one process is on the CPU. We also see that the CPU is idle 86.1% of the time.

    The following top output, collected when the command was run on a Solaris system, also includes a different report on CPU states:

    last pid: 27211; load averages: 0.02, 0.03, 0.04
    CPU states: 94.1%idle, 0.9% user, 9.4% kernel, 0.4% iowait, 0.0% swap CHECK THIS^^^

    We can see that the CPU on this system is also idle most of the time and that the load averages are low, indicating almost no competition for processor time. We also see that little time is spent waiting for I/O completion (iowait). These results all add up to a system that is far from overloaded.

    Establishing a watershed dividing acceptable and poor performance is a major frustration when trying to gauge performance. Or, more realistically perhaps, when a system is noticeably slow, we might not know when we can point our fingers at a particular performance statistic as indicative of the cause.

    As a general rule of thumb, if load averages consistently exceed three times the number of CPUs on your system, your CPU is overworked. Averages less than 1 are acceptable. On the other hand, a slow system with a CPU that is idle much of the time is probably suffering from slow I/O.

    By Sandra Henry-Stocker
  3. luvhuffer

    luvhuffer TechSpot Paladin Posts: 443

    If you are using a gig of RAM go to system properties open the advanced tab, hit the settings button and go to the advanced tab. Make sure you are using at least 1535MBs of virtual memory. Also under memory usage see if it's set to best performance of programs or system cache.

    With just the desktop open and no programs running hit ctrl+alt+delete and look at the processes tab. Is anything running that's using 20000k of memory or more?

    When the system freezes up, are you sure it's a memory usage problem? Have you checked event viewer to see if it's the iTunes program that's causing the freeze?

    Go to start/run and type in msinfo32.exe and hit OK. When the system information window opens expand Software Environment and click on Windows Error Reporting. Anything showing up?
  4. magsker

    magsker TS Rookie Topic Starter

    yea, when I check windows error reporting there are a bunch of application hang entries for itunes. There are also a few for wintasks.exe.

    Also I am usuing 1536mb of virtual memory and it is set for performance.
  5. howard_hopkinso

    howard_hopkinso TS Rookie Posts: 24,177   +19

    Hello and welcome to Techspot.

    Just to eliminate any possible virus/spyware problems, do the following.

    See this thread HERE.

    Then, post a fresh HJT log into this thread.

    Regards Howard :wave: :wave:
  6. Mr Papschmere

    Mr Papschmere TS Rookie Posts: 55

    Run the spyware tests.

    You can also stop a lot of background stuff loading up with Windows.


    you can untick any superflous entries - like Adobe Update, Java Update, any non essential stuff really - - - - DONT untick your firewall/antivirus though!
  7. luvhuffer

    luvhuffer TechSpot Paladin Posts: 443

    Go to start search and type in wintasks.exe. If it is in the c:\windows\system32 folder then it is a virus/worm, and needs to be dealt with. wintasks should be in your Program Files folder, if you downloaded and installed it.

    Do you use iTunes software? It sounds like it need to be reinstalled if a lot of errors are pointing to it. The drivers may have been corrupted. If you don't use it then uninstall it and Quicktime, and do a fresh install with the QuickTime Stand Alone Player that you can download here. It doesn't come with all the iTunes baggage.
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