Vista - Monitor causes strangely high CPU usage

My computer (Dell XPS 1330) runs fine without the monitor (Dell 20" SP2008WFP) but intermittently hits 100% CPU usage with the monitor plugged in - usually if I am running more than 3 or 4 standard office programmes - and then returns to running normally if the monitor is unplugged. I have 4GB of RAM and 2 x 2.5 GHz processors, so don't think this should be a problem. The laptop and monitor seemed to work fine together for a few months but subsequently the problem got progressively worse over a few months.

I have tried stopping all processes in TM when the problem occurs - none stand out as being the culprit. The only common occurrence is that the task manager process itself runs at 20%+ to 40% CPU usage when the problem occurs. I have already tried defragging, spyware, cutting out all visual effects and all sorts of other performance improvement options - I even totally reformatted the hard disk before I realised that the problem was related to the monitor being plugged in! I have tried rolling back and then re-updating the drivers for the monitor and the display adapters, but the problem persisted. Any idea of other ways of attempting to solve this problem?

Congrats! The "weirdest problem of the day" award is yours

Is the processor always pegged at 100% while the monitor is plugged in or does it fluctuate?

If it's not constant, is there anything that you know of (some act - doing something specific) which will cause the processor utilisation to start or to increase?

If you boot to safe mode, does the same issue occur there?

Is the BIOS version up-to-date?

thanks for the award H2

the CPU fluctuates - computer starts off working fine but then CPU slowly builds up until it eventually jams at 100% and gets stuck there until you unplug the monitor or switch it off. it can take anything from 30 mins to a couple of days for the CPU to get jammed. There seems to be nothing consistent that sets it off other than using more than minimal resources. clunky programmes might be causing it, for eg. CPU jammed when i started using itunes today and it also jammed when streaming video from BBC news with Google chrome. However, it also jammed today when i was just using outlook and Word.

the issue has not occurred in safe mode in the past, but i have not remained in safe mode for that long - I will try working in safe mode al tomorrow and see if it gets jammed then.

BIOS is up to date - version 15 or something that was released recently if that means anything to you.

Should my video card be able to handle a 20" monitor - based on the info on my display adapter - I have 128MB of dedicated video memory and total available graphics memory of 1663MB, if that means anything.

Wow.

I don't think your problem is caused by hardware horsepower, or rather the lack thereof. There should be no reason why even the puniest of video cards would cause ever-increasing processor utilisation - as long as the card itself is not damaged on a hardware level, which is conceivable in this instance.

In addition to the safe mode question, I'd be interested to know a few other things:

- Does the processor utilisation get ascribed to any particular process at all? You mentioned chrome and Office apps. Do you actually see Task Manager reporting chrome, Outlook, or Winword as the processor utilisation offenders, and does ending those processes reduce the processor levels?

- In TM, on the performance tab, click View/"Show kernel times". That will add a red line to the processor utilisation graph - time spent specifically in kernel-mode. When the processor is getting pegged at or near 100%, is the red line up near 100%, in the middle, or closer to 0%?

- Done a good, thorough malware scan lately?

Thanks H2

Another strange thing - just after the computer has been booted up or woken up from sleep, I can start up loads of programmes and the CPU usage barely breaks sweat, i.e. stays v close to 0%. The 100% CPU usage problem only seems to kick in after I have been using the computer for more than around 30 mins at least.

- Regarding processes that are using CPU when it gets jammed at 100% - no clear culprit from my memory, although the task manager process is always much higher than usual – 20-40% every time and is always the process that is taking up the most CPU. Then the other programmes that are open take up more CPU than they usually would. If you kill off each process one by one – you can eventually get the computer back to running normally but you often have to kill off some system processes like svchost.exe or rundll32.exe. Ending the processes of outlook, winword, chrome, itunes and other open programmes normally does little to change processor levels when it is jammed at 100%. I will check this again next time she crashes.

- Regarding kernel memory usage – I will let you know where the red line is once the CPU jams again, but right now everything is working like a dream!

- Regarding malware - I scan the computer and external hard disk weekly with Kaspersky IS. I also scanned with some free malware software after this problem kicked off. Before I realised that the problem was connected to the monitor I ran out of solutions and completely formatted the hard drive, wiping everything. I then did not connect the computer to any external hard drives or the internet and only connected it to my monitor, mouse, and keyboard assuming these cannot carry any malware (I may be wrong!?). The CPU jam came back nonetheless and that is when I realised it was something to do with the monitor as I unplugged everything one by one. I had kind of ruled out malware as when I am working remotely and the laptop is on its own, it will run absolutely fine for weeks.

- Regarding safe mode, I will switch to that once I have had my next blow out and seen what happens to processes and kernel memory.

Thanks again.

So, today all worked perfectly for about 4 hours and then the usual, computer begins to slow down, TM process begins to take up increasing CPU until CPU is jammed at 100% after a couple of mins. I noticed that this happened just after I had downloaded and installed some updates from yesterday for Windows Defender.

None of the open programmes/applications (chrome, outlook, excel, word) were the culprits in terms of CPU usage. CPU is occupied by taskmgr, svchost, perfmon, googledesktop, rundll32 and avp.exe (this is kaspersky). I closed all programmes - this unjammed CPU but only temporarily. I then ended some processes: svchost, rundll32 and googledesktop. These, again, only momentarily unjammed the CPU. I then pulled out my internet cable and exited kaspersky. This returned the computer to normal operations. I have now reconnected to the internet and re-enabled kaspersky and everything is working fine!

I also checked out the kernel memory usage while the CPU was at 100% - the red line was running at roughly 50%, varying between 20%-60%.

I will switch to running in safe mode shortly.

By the way - when the problem occurs and I shut down and restart the computer, on restart my quick launch bar comes back all mixed up, taking up most of the task bar and with all the programme shortcuts re-ordered! weird huh?

I look forward to any suggestions you might have. Next time I crash I will try just closing down Kaspersky to make sure that is the culprit. Could it be conflicting with the monitor somehow? Or do I need to re-scan with some anti-malware - any suggestions which one and preferably free.

thanks

back again for cpu jam II of the day, about an hour after the first jam. It may be in my head, but the computer seemed ever so slightly clunky in between crashes. The same problem occurred again, triggered by chrome vidoe streaming this time. After it had jammed at 100% I disconnected the internet cable but did not shut down kaspersky. This fixed the prob and CPU returned to almost 0% ... any suggestions? It seems that there is something wrong with the connections on that side of my computer!? The monitor cable and internet cable go into the computer next to each other.

All working fine for now.

Just to add - this is very strange as I worked with an internet cable but no monitor all last week and the week before without any problem at all. Therefore, maybe it is something to do with the number of connections - this makes no sense to me - could it be something to do with the hardware and drivers for these ports?? Any suggestions?

Excepting the "hardware problem" special case, processor utilisation is caused by direct instructions from software, and not by things like monitors and other peripherals. Something like a keyboard could conceivably be issuing hardware interrupts at a high rate, which would in turn cause the keyboard interrupt handler (driver) to chew the processor, but again it's the software (the driver) which is directly responsible.

I'd say your problem falls into one of 3 broad categories:

1) The hardware is borked. That can manifest itself in almost any weird and wonderful way, including your symptom. That's what the safe mode test is supposed to show - does it still happen even with a base set of drivers and apps, in which case hardware becomes a more likely culprit. The fact that the symptom survived a complete reinstallation also suggests a possible hardware link.

2) A bad driver. No legitimate software would inject itself into so many other processes. The only way that Outlook, Word, svchost, chrome... can all seemingly be affected is a kernel-mode driver which executes in their thread context(s).

3) You've been pwned and your machine is being used in tit-for-tat pesky haxx0r DDoS reprisals by two 13 year olds from upper Moldavia.

If the cause is software (as opposed to broken hardware), this is just about the only (free) tool which can help track it down, but it's not the simplest thing ever:

http://www.microsoft.com/whdc/system...rf/krview.mspx

Let's hope it doesn't come to that. I'd suggest that for now you run in safe mode long enough to check whether it happens or not. Leave it running in safe mode overnight perhaps.

Thanks H2

I tried starting up in safe mode with and without networking. Initially in both of these modes the CPU went straight to 40%+, hitting 100% but not jamming there as per usual. The task manager was the main culprit in terms of process usage. The only other processes taking noticeable amounts of CPU were explorer and a csrss, but these took up minimal CPU. I tried unplugging everything but the CPU remained high - I found this bizarre as I have never encountered the high CPU problem while using the laptop alone disconnected from external monitor, mouse and keyboard. I switched the computer off and went away for a few hours and have just rebooted in safe mode with networking - currently the computer is working well with close to 0% CPU usage - I will leave it running the rest of the day and all night and see if the problem recurs?

So - I guess we are probably looking at a hardware problem?