Intel Core Duo USB Issue: A Mischaracterized Bug
by Anand Lal Shimpi on February 13, 2006 1:40 PM EST- Posted in
- Laptops
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.
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.
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Mezcal - Tuesday, February 14, 2006 - link
Hello, I tested perfmon after reading your test. I own an Acer Aspire 5024 with a Turion 64 ML34 inside. So, I was wondering if this could cause me any battery problem. After testing Perfmon with % C3 time with USB wireless mini mouse, I can see a graph with mountains (between 60 and 100%) while the USB mouse is not plugged in and completely flat (0%) while plugged in. So, this may be the result of the problem you described? No?I didn't test the battery life with the USB mouse plugged in and without it 'cause I can't find any utility to test that. So, I can't say if it affects the battery life.
IntelUser2000 - Tuesday, February 14, 2006 - link
According to AT, it means Turion systems also have the same problem as the Centrinos in terms of battery life reduction when USB 2.0 devices are connected. Since % mean HOW OFTEN THE CPU IS IN LOW POWER C-STATE, 0% means its not going into low power states AT ALL, while 60-100% means its going into low power state 60-100% of the time.
NullSubroutine - Monday, February 13, 2006 - link
I am awaiting my new Dell Inspiron E1705 (2ghz Duo, 2GB 667mhz, 80GB SATA 7200, Ultrasharp 1920x1200, 7800GTX Go) I hope this issue has a better fix because it seemed the fix didnt work will with this system. I think the USB hub that is built into the system may be the cause of this, hopefully Anand can get the review of this system and see if he can fix. Personal request if anyone reads this, apply new artic silver on the cpu/gpu then see how much cooler it runs, and how much more you can overclock the gpu...pretty please...IntelUser2000 - Tuesday, February 14, 2006 - link
quasarsky - Tuesday, February 14, 2006 - link
weird. u say c4 is the 'sixth' power state. 0,1,2,3,4. sounds like it would be fifth. ???? am i missing something here?IntelUser2000 - Tuesday, February 14, 2006 - link
Anand said this:
For Pentium M
C0
C1
C2
C3
C4
Core Duo adds: deep C4
Coldfusion - Monday, February 13, 2006 - link
Or is it strictly a Windows issue?bobsmith1492 - Monday, February 13, 2006 - link
Wow.. so maybe this explains why my battery life is so different now than when my computer was new - I swear, when I first looked at it, it was saying 7 hours and I got like 5 when doing normal activities. With my mouse, though, it's more like 3-4... of course, it's a year older also. (P-M 1.7 Dothan)How can you tell whether or not a device is USB 2.0? I'm sure something in the device manager says, but I can't tell..
huges84 - Monday, February 13, 2006 - link
Why is it that the two Asus systems that are the same, except for motherboard and a slight difference in memory speed, showed that the Sonoma platform had better battery life than the Napa platform? I know it isn't much difference, but shouldn't the Napa be noticably ahead of Sonoma?Does the memory difference make that much of an impact? Or are the power consumption improvements in Napa pretty much only for when the processor is basically completely idle? If so then I don't think many people will see the extended battery life. Unless you like to leave your computer idle when it is running on battery. Maybe the improvements are also on the upper end and it is just the middle ground that didn't get improved. How high is CPU utilization in this test?
IntelUser2000 - Tuesday, February 14, 2006 - link
Well the difference is within margin of error. While W5F based on Core Duo gains less than W5A based on Pentium M, the difference is very little, less than 15 min.
Lenovo shows better results. T60 based on Core Duo always gets slightly better than T43 based on Pentium M, whether before or after, and T60 can support higher resolution, otherwise identical components.