Linked by Thom Holwerda on Mon 8th Feb 2010 23:55 UTC
Windows The past few weeks or so, there's been a lot of interest in a supposed battery status report bug in Windows 7. After installing Windows 7, some users reported seeing "consider replacing your battery"-warnings in systems that appeared to be operating just fine on Windows XP or Vista. After extensive research, Steven Sinofsky has now explained on the Engineering 7 blog that the fault is not with Windows 7 - it really, really is your battery.
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RE: Two issues
by darknexus on Tue 9th Feb 2010 03:09 UTC in reply to "Two issues"
darknexus
Member since:
2008-07-15

I can't say I've seen a 50% decrease, but I've seen some issues where by Windows 7 will not get as much life out of a battery as XP or Linux. I've seen about a 15% reduction on some machines, and I'm 99.99% sure that it wasn't due to an unhealthy battery. I suspect, personally, it was the result of badly-behaved acpi bios coupled with no acpi drivers for win 7 on those machines, while XP and Linux both had support for all the ACPI features once configured. As is typical with Windows, the majority of problems aren't caused by Windows itself but by incompatible and/or poorly-written drivers. Other than Malware, drivers are the number one problem I see when dealing with Windows and I suspect it is mostly that to blame for reduced battery life under 7 on a lot of machines.

Reply Parent Score: 2

RE[2]: Two issues
by umccullough on Tue 9th Feb 2010 03:41 in reply to "RE: Two issues"
umccullough Member since:
2006-01-26

I suspect, personally, it was the result of badly-behaved acpi bios coupled with no acpi drivers for win 7 on those machines, while XP and Linux both had support for all the ACPI features once configured. As is typical with Windows, the majority of problems aren't caused by Windows itself but by incompatible and/or poorly-written drivers.


I'm fairly certain that, unless the manufacturer of your BIOS is an idiot, ACPI-based power management shouldn't really require any special drivers. I mean, that's sort of the whole point of standardizing that isn't it?

I've read that some BIOS will serve up different ACPI tables based on the OS they detect is running. A lot of retarded manufacturers have hardcoded their ACPI tables to spit out something different if they don't detect Windows XP... perhaps that is what you're referring to?

I've rarely installed the crapware "battery/power management" software that comes with a laptop - more often than not it provides little benefit over the stock features, other than providing some fancy UI and some extra software-based "profile" features for those who like to fiddle.

Edit: OK, I suppose some of those crapware programs probably replace the "missing" functionality from Windows XP - but from what I read, Windows 7 supposedly fills that gap again.

Edited 2010-02-09 03:43 UTC

Reply Parent Score: 2

RE[3]: Two issues
by darknexus on Tue 9th Feb 2010 03:52 in reply to "RE[2]: Two issues"
darknexus Member since:
2008-07-15

ACPI is standardized in theory, but hard-coded tables are only one of the issues. Some ACPI bioses behave badly, either not responding to certain functions or returning bad information. Typically these machines come with Windows drivers that compensate for it. I'm not talking about the crapware power management utilities but the driver component itself. Also, just because a system has ACPI bios doesn't mean you're machine will adjust itself (scale back the CPU and/or FSB when not needed, etc). This, too, typically requires a driver or utility as the os itself doesn't often handle it. In the case of Windows this is taken care of by installing drivers, in the case of Linux and other *NIX oses you need to configure the CPU frequency scaling and FSB scaling yourself if there's no utility to do it for your machine. ACPI is a standard at least on paper, but it merely provides the os a way to communicate with the ACPI bios and through there control the system's power management. It doesn't do much on its own. This is in contrast to APM which was used before ACPI became commonplace, which handled a lot in the bios itself and much less through the os. Having dealt with both of them, I'd say I prefer ACPI (even buggy ACPI) over APM.

Reply Parent Score: 2

RE[3]: Two issues
by cerbie on Tue 9th Feb 2010 05:53 in reply to "RE[2]: Two issues"
cerbie Member since:
2006-01-02

I'm fairly certain that, unless the manufacturer of your BIOS is an idiot, ACPI-based power management shouldn't really require any special drivers.
That may be, but there are tons of HP and Compaq notebooks out there that might qualify for having idiotic BIOSes, and require special drivers, often only available for Windows XP (and, often, even APM won't work, in Linux).

Reply Parent Score: 2

RE[2]: Two issues
by leavengood on Wed 10th Feb 2010 02:35 in reply to "RE: Two issues"
leavengood Member since:
2006-12-13

Other than Malware, drivers are the number one problem I see when dealing with Windows and I suspect it is mostly that to blame for reduced battery life under 7 on a lot of machines.


It is pretty ironic, yet not surprising, that one of the top problems with Windows 7 is lack of drivers, since that is also the top problem in "alternative" OSes. I wonder when these hardware manufacturers are going to get it through their thick skulls that producing hardware and drivers which only works with Windows XP is stupid. They should at least document how there crappy hardware works so other people can write proper drivers.

Reply Parent Score: 1