Question:
Core Duo and USB battery drain
I've seen reports that there is an issue either with the USB chipset drivers withing Window or the Duo chip itself that causes excess battery drain when any device, even one that doesn't draw much power (i.e. memory stick), is connected.
Anybody else seen anything else about it? I'm leaning towards the FE with the Core Duo, but I'd like to know what is up with this before buying.
Answer:
Re: Core Duo and USB battery drain
Im leaning towards that too... This has been discussed several times before. Do a search or check the Hardware section.
Answer:
Re: Core Duo and USB battery drain
From what I've read sebush... windows has had an issue with the power management of connected USB devices for a while. Something about not putting them on lower power mode when they aren't in use.
The issue has existed since the early days of centrino, but has only come to light since laptops began using the napa platform (the core duo's platform).
Microsoft have said they are aware of the issue, but have not said if they are working on a fix for it or not. My guess is that this will be a high priority for them. But no concrete information is available.
As for the amount of battery drain, its very significant when a deivce is connected to the usb port. I vaguely remeber anandtech doing a test and finding that the battery life drops by around an hour when a usb hard disk is connected (and not in use).
With all that said, this is too significant an issue for microsoft and intel to be overlooking. Intel's entire campaign is based on performance/watt, dual cores and most importantly a much higher battery life. My guess is they'll be working overtime to get this issue fixed. But I can't imagine why they haven't issued a statement regarding whether they are working on a fix or not.
cheerio :)
Answer:
Re: Core Duo and USB battery drain
Hi,
I found this site when looking for the USB issue:
http://www.tgdaily.com/2006/01/28/to...r_drain_issue/
It's a bit long, so I'll quote the main phrases:
The specific piece responsible for the power drain is Windows' Advanced Configuration and Power Management Interface (ACPI) driver, which is a software component provided through the operating system. This is the component responsible for instructing a device to power down when it is not in use. Under ACPI, there is a series of sleep states that the operating system's ACPI driver recognizes and supports.
The issue, according to Microsoft, concerns the asynchronous scheduler component - a part of the USB 2.0 driver that determines when devices can access local memory. With the revision to that driver implemented in Windows XP Service Pack 2, the scheduler can inadvertently be left running. As a result, Windows' internal task scheduler (a separate item) treats the asynchronous scheduler as a running process involving the attached device, and thus stops itself from ever giving the processor the signal to power down, or power lower - to slip into one of its ACPI sleep states. Because the scheduler is running, Windows thinks the system is continually busy. As a result, the computer can use more battery power.
It seems that the solution could be very simple: a simple addition of a single key to the Windows System Registry.
So, this is the question: Microsoft knew about this problem since 12 July 2005 (as Knowledge Base article KB899179), why does they don't fix this bug yet?
Intel has asked Microsoft "to fix the registry to make the problem go away." In the meantime Intel is working to fix the issue by itself: "We are doing additional work on our end to see if there is anything we can do to overcome the same challenge Microsoft is having".
I have just ordered an ASUS A6JA, so I hope the problem will be fix as soon as possible.
Goodbye
Answer:
Re: Core Duo and USB battery drain
hey people!
I know that some of the forum members have actually bought Core Duo Laptops... can someone please check if this actually happens and how much of an impact it has based on your experience?
I think it will be good to have some members check it firsthand and give information on this!
Answer:
Re: Core Duo and USB battery drain
I seem to recall something about this only being an issue when sleeping, but I may be wrong. Can anybody confirm?
Answer:
Re: Core Duo and USB battery drain
Hi TheRunaway,
I think you are wrong. If you read my previous post you can see the main point of the issue.
The Centrino(R) technology, since its first version, was based on the action of powering down a device when it is not in use. With Sonoma and now with Core Duo this technology improved a lot, in fact Core Duo has five different "sleep state", depending on the use of the different devices.
The problem is that the asyncronous scheduler (used to manage the USB device access to local memory) can be left running; in this case the Operating System can "think" that your system is busy (even if you are using 2-3% of CPU computational power) and it don't give the "power down" signal to the processor.
The result is that your CPU will never sleep and it will use more battery power.
Talking about the tejaspadekar's question:
I'll have my notebook next week, so I can't answer to you, but if you follow the link I posted yesterday you will see a couple of benchmark result.
Battery life without USB2.0 device:
- Napa (Core Duo T2300): 4:24
- Sonoma (Pentium M 750): 3:08
Battery life with active USB 2.0 device:
- Napa (Core Duo T2300): 3:06
- Sonoma (Pentium M 750): 2:51
While the Sonoma notebook only lost 17 minutes of battery running time with the drive connected, the Core Duo notebook's running time decreased by a stunning 76 minutes.
Answer:
Re: Core Duo and USB battery drain
Thanks, Haldo!
However, I'd prefer if someone actually uses one and then gives his/her personal opinion. I'm not too hot on media supplied information being entirely accurate. (With all due respect to everyone!)
Thanks again... and will wait for your post once you are able to test!