The engineers responsible for Intel's Core Duo processor and Centrino Duo platform are a bit frustrated.  Years of hard work leading up to the platform's launch in early January was first plagued by the problem of availability.  Core Duo and Centrino Duo notebooks are still not widely available, and that will continue to be the case at least for another week or two.  Outside of availability, another even more troubling problem crept up - could it be that the Core Duo platform had a bug that significantly reduced battery life when paired with any USB 2.0 device?  The folks at Tom's Hardware originally uncovered the issue, when they noted that battery life on their ASUS Core Duo notebook dropped dramatically after merely connecting an external USB 2.0 device. 

How much more frustrating could things get?  After spending years of work on a new mobile CPU and platform, your customers still really can't buy them and the one thing that everyone remembers about them is that they have some sort of a bug that reduces battery life.  When you've spent a good deal of your design time trying to increase battery life, having a reputation of decreasing it before notebooks are widely available has to be a tough pill to swallow. 

However, the case isn't as open and shut as that; the original test data indicated that this was primarily a Core Duo problem, while Microsoft insists that the problem should affect all notebooks.  The other issue is that, until last week, every single Core Duo platform that we could get our hands on was pre-production.  There's also the question of whether or not the problem is caused by the actual USB device used.  And finally, amongst all of this debate and finger pointing, a temporary solution actually existed, just begging to be tested. 

We set out on investigating this issue immediately after it was discovered, but soon found out that it was a lot more complicated than we thought upon first glance.  We've spent almost the past two weeks performing non-stop battery life testing on five notebooks with up to 4 different USB devices, testing theories, trying to pinpoint exactly what causes this problem and testing Microsoft's fix.  What follows is the process that we went through in our labs when faced with this strange bug.

Starting at the Beginning
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  • krwilsonn - Wednesday, February 15, 2006 - link

    I just read their new article and apparently they were tipped off by some "insider" about the problem and then went ahead and "discovered" and published it. That is what it says at the end of their article, anyway. Their forum thread that is linked has some comments from an editor or someone that are also interesting. I'm sure everyone is checking it out but for those that haven't you should for the sheer humor of it.
  • mino - Tuesday, February 14, 2006 - link

    1.) Installed new hp6220 custom configured an hour ago.
    Platform i915G - Sonoma

    Provided Perfmon detects C3 correctly (showing curve around 98% at idle) this system may not bee affected.

    I've installed HP's "System Enhancements Disk" package, so some workaround by HP may have been included. (the regfix is not present)

    However I have no way to prove Perfmon is correct.

    2.) nx6125 I've upgraded from home to Pro last week so it is HP install just a little sripped one

    the system spend around 96% of its time at idle in C1, seems wierd to me. No time is spent in C3 also. Maybe somne HP stuff keep the CPU busy.

    Both systems are used with Bluetooth mouse via an integrated adapter.
  • mino - Tuesday, February 14, 2006 - link

    Just now I observed on nx6125 that the moment Intellimouse Explorer for Bluetooth goes into power save mode (after ~1 minute of inactivity) Turion goes from 96% in C1 to 96% in C2.
    Strange as it may seem nothing like this happens on Sonoma platform. I sense ATI SB400 does have something say about it.

    Another thing is that the moment CPU starts using C2 intensively, the idle power consumption goes from ~15.6W to 13.2W which is pretty serious amount of power wasted.

    Anand, I suggest you do not waste your time by testing battery life when you revisit this issue, to prove assumptions you may use Perfmon's Battery Drain counter.

    HMM, funny is, the nc6220 does not show the battery counter present in Perfmon.
  • mino - Tuesday, February 14, 2006 - link


    sripped == stripped

  • artifex - Tuesday, February 14, 2006 - link

    as soon as you get an MBP in for testing :)
  • zsouthboy - Tuesday, February 14, 2006 - link

    Not that its as big a deal for desktops, but mine seems to be doing the same thing when my USB 2.0 mouse/kb is plugged in...

  • krwilsonn - Tuesday, February 14, 2006 - link

    Are you being serious??
  • kmmatney - Tuesday, February 14, 2006 - link

    Yeah, I've noticed my Prescott's been running a little hot as well. Damn USB 2.0!
  • blwest - Tuesday, February 14, 2006 - link

    Yay, yet another "feature". If you run Microsoft Winders, we gurantee shorter battery life.
  • dualathlon - Tuesday, February 14, 2006 - link

    Hi, i own an dell inspiron 9300, pen M 760, geforce 6800go. When i enable that registry key, i experience heavy pointer delay when playing Counter Strike Source. I tried both logitech mx510 (wired) and logitech mx900 (bluetooth wireless, paired with dell internal BT and logitech hub as well).

    I see no delay in office apps, FYI. I haven't test battery life with that key though.

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