Kernel Bug Means Linux Power Usage Remains High 179
An anonymous reader writes "The significant Linux kernel power regression reported back in April, which ended up being attributed to PCI-E Active State Power Management, is still not resolved even as Ubuntu 11.10 and Fedora 16 approach. Until Linux is able to handle ASPM in a manner more like Windows or the device drivers explicitly set the ASPM flag, users of many modern laptops need to use the "pcie_aspm=force" option to regain much of their battery life. At least a power bug affecting newer Intel hardware with the "energy performance bias" feature has been fixed. There's more information in this LaunchPad bug report and in the latest power consumption testing."
It is not something that can be resolved... (Score:5, Informative)
It's a problem with the BIOS manufacturers, and the BIOS incorrectly reporting its ASPM capability. When an OEM installs Windows on a laptop, it can correctly tune these settings. But for a fresh install of Linux that YOU performed, a database of every motherboard + BIOS combination needs to be maintained in the open to set the force PCIE ASPM flag. If set wrongly, when the BIOS doesn't support it, it could lead to locking which is far more serious.
There are other solutions to effectively manage power in Linux, like Jupiter [jupiterapplet.org].
For more (and better) information, see the following links: About the Kernel 3.0 "Power Regression" Myth [fewt.com] and PCIe, power management, and problematic BIOSes [lwn.net]
Re:You mean Moronix, right? (Score:1, Informative)
Phoronix testing of video devices has been very helpful to me. The state of Intel and AMD video drivers is analysed in enough detail to make good decisions about hardware for embedded systems. I've found high correlation between my own test results and those of Phoronix.
Re:absolutely....buggy BIOS's are the problem (Score:4, Informative)
It's pretty well established that the ACPI implementation that MS was using with Win XP was non-standard. The one that folks had access to wouldn't compile the DSDTs that were coming with a lot of the computers because they were buggy and non-standard. MS had the advantage of controlling the only validation program that mattered and could hard code into their OS the bits necessary to work with the most common bugs.
Unfortunately for Linux, *BSD and everybody else, those coders didn't have access to that information and had to go to a huge amount of work to rewrite the DSDT and load that so that it would work as the standard specify.
Also, nice ad hominem you've got there, I am not a Linux fanboy,