Intel Core Duo USB Issue: A Mischaracterized Bug

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• Eris23007 - Monday, February 13, 2006 - link

  P.S. That's why you read more than just the intro and conclusion pages before asking questions.
  
  "RTFM"

• DigitalFreak - Monday, February 13, 2006 - link

  Ha!

• Eris23007 - Monday, February 13, 2006 - link

  The USB hard drive they tested with had its own power supply. The "USB Drive" was a flash device (USB bus powered), while the "External HDD" was:
  
  

  quote:
  

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  Vantec NexStar 2 External 3.5" Hard Drive Enclosure (USB 2.0)
  
  Note that this device is entirely externally powered
  

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• UNCjigga - Monday, February 13, 2006 - link

  I will have to do some testing on my notebook with the 'workaround' fix installed. I could have sworn that around the time I installed SP2 on my lappy the battery life suffered, but this was about 6-12 months after I got it so I just figured the battery was getting old.

• Ionizer86 - Monday, February 13, 2006 - link

  Wow, this is getting interesting. I'm surprised that this bug affects 915 based systems too. I wonder if this could be a broader issue that may affect intel 855 systems or AMD-based computers with chipsets from other vendors. I suppose I could do some playing around

• Ionizer86 - Monday, February 13, 2006 - link

  No edit button... (accidental post before completion).
  I could test this out on my 855 based laptop if only I had Perfmon and the special plugin :)

• Ionizer86 - Tuesday, February 14, 2006 - link

  Specs: Thinkpad R50e, Pentium M 1.5 on i855GME.
  
  I booted into Windows normal mode as cleanly as possible and ran Perfmon. The CPU was usually in C2 ~60% of the time and C3 ~35% of the time, for a total of ~95% in C2 or C3. Upon plugging in any of my USB stuff (an external hard disk, a Sandisk Cruzer mini, or even my IBM mouse), I'd get 95% in C2 and 0% in C3. Maybe my mouse is a USB 2.0 mouse; not sure.
  
  Battery draw goes from about 11.7W to 12.5W when I plug in my mouse.
  
  By adding the registry key, I no longer have the issue with the Cruzer or my external hard disk, but the problem with the mouse remains.
  
  Looks like MSFT has quite a problem at hand.

• Accord99 - Tuesday, February 14, 2006 - link

  0.8W, maybe its the power draw of the mouse itself?

• johnsonx - Monday, February 13, 2006 - link

  Adding to what Jason said, you only need the 'secret' plugin for Core Duo processors. The C3 state counter that Perfmon already has works fine on older platforms.
  

• IntelUser2000 - Tuesday, February 14, 2006 - link

  quote:
  

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  Adding to what Jason said, you only need the 'secret' plugin for Core Duo processors. The C3 state counter that Perfmon already has works fine on older platforms.

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  Not just Core Duo, but: "As you can probably guess, Perfmon is inaccurate in this case. While Perfmon does a fine job of monitoring C3 states for older processors, it fails to handle properly the CPUs we're most interested in: the Pentium M and Core Duo."