CPU slows down when power is connected

I have had my M17x for some months and everything has been working just fine...until yesterday. When I started the laptop (power connected) it was running reaaaally slow. CPU going up to 100 for every task, can't even play a vga-movie without stuttering. Sooo, I looked at the power mode, it was still running high performance, using discrete graphics and everthing seemed ok. ...well i restarted and guess what, then it run just fine.
But today I got the same problem and a restart or two, or three or.... didn't help. BUT if I unplug the power cable it speeds up and are running just fine (power mode not changed). When I connect the cable it slows down again. Anyone that has a clue what could be wrong?

EDIT: I can add that when the power cable is connected the core speed is 1000-1600MHz instead of the 2666 MHz it should and does run at when power isn't connected.

Thanks for any help.
/Fre3de

 

Uninstall the Command Center.

 

Can you double check if stealth mode is disabled?

 

Command Center has nothing to do with the frequency of the processor cores, has it?

 

When it run slow I also thought it was stealth mode. But unfortunatelty stealth mode is not on. AND the cpu is downclocked a lot more than what stealthmode does. The problem is that it never goes over 1600MHz... My best guess is that the power adapter is broken...the computer gets wrong power input which affects the intel speedstep technology in some way. But i don't think you can disable that in bios. I will take a look though...

 

Uninstall it

 

Review your Power Profile settings - both in CC and Windows. Look at the settings for CPU Min / Max % based on Power Source.

Also, keep in mind that Intel SpeedStep is at work here also. If the CPU does not need to be @ 100%, then it will scale back.

For the Power Adapter, boot into Diagnostics - and run the Power Adapter test.

Alienware 32-Bit Diagnostics
vA1354A1, Last Updated: 06/15/2009
Install to a USB Flash Drive for quick booting into the Dell Diagnostic Suite designed for the M17x. Much more detailed than the basic tests offered via the BIOS Diag Boot option.
ftp://ftp.us.dell.com/diags/AW1354A1.exe

 

It sounds like a bug in the stealth/ battery mode system.

 

The first thing I did when i got the laptop was to create an own power profile setting where CPU Min and Max are both set to 100%, both when power isn't connected and when it is. Since then I have not changed anything and the last week I haven't installed anything (at least not what I can recall) but suddenly the CPU will never go above 1600MHz when power is connected. I don't think this is a software issue but a hardware failure of some sort. Googling the issue I have found some other guys with the exact same problem and a change of power adapter solved their problem. I will contact dell/alienware today and keep you updated about the process.
Thank you everyone for your help and I really like the high activity on this forum.

I will boot into diagnostics and run the power adapter test when I get back home later tonight.

 

Why don't you try what aikimox suggested bofore going into so much trouble?

 

Sorry, forgot to say that Command Center hasn't run on my computer for a long time. My previous thread on this forum was about me not getting command center to work properly so I uninstalled it. Still I wanted to know why he thought Command Center could have something to do with the problem.
Why I cannot use Command Center probably is because I have Swedish OS. (I don't understand why I didnt choose to install english OS, must have been a moment of insanity). Still it's very bad that alienfusion and all that stuff doesn't work just because of OS language settings. For example I have never been able to create my own lighting scheme with that gui. I had to edit those files "manually". But that's a different story.

 

it's a little OT but you can change your windows language if you have ulitmate installed.. Go to optional updates and download english language pack.

 

Unfortunately I am running Home Premium and not Ultimate or Enterpise so I don't think I can change laguage pack.

My dell contact said that he hadn't heared about the problem before but recommended me to update to BIOS A03 and nvidia beta drivers. I have followed the dpc-latency story but since I haven't had any problem at all I haven't upgraded bios or video drivers. Im a software engineer myself so I know that when you get a configuration that is working very well you better not upgrade without a good reason. But I guess I have to try at least the new bios before they are willing to send me a new power adapter.