Red Hat Bugzilla – Bug 90593
IBM ThinkPad T40 Pentium-M Always Minimum MHz
Last modified: 2007-04-18 12:53:38 EDT
From Bugzilla Helper: User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.2.1) Gecko/20030225 Description of problem: I just laid hands on a new IBM ThinkPad T40. It is a Pentium-M model. In the BIOS, I set the power saving mode on the CPU to "automatic", which is supposed to turn the MHz up when necessary and down when not. In Windows, it lives at ~600 MHz normally, and if I start a compile, jumps to 1600 MHz immediately and is extremely responsive, and returns to ~600 MHz when compile completes. In Red Hat Linux 9, it lives at 600MHz always, judging by /proc/cpuinfo. If I start the same compile, the mouse and keyboard become extremely unresponsive (10-30secs between events), and /proc/cpuinfo still shows ~600MHz. If I go into the BIOS and set the CPU power saving to "optimal performance", it runs at 1600MHz always (again, judging by responsiveness and /proc/cpuinfo), but the battery life is significantly shorter (30%+). Version-Release number of selected component (if applicable): kernel-2.4.20-9 apmd-3.0.2-18 How reproducible: Always Steps to Reproduce: 1. In BIOS, set CPU power saving to "automatic" 2. Boot into Red Hat 9 3. Run a large compile Actual Results: mouse and keyboard are extremely unresponsive, /proc/cpuinfo shows ~600 MHz Expected Results: UI responsive, /proc/cpuinfo shows ~1600MHz during compile, returning to ~600 Mz afterward Additional info:
Without information on Intel on the Pentium-M frequency scaling, this won't work under Linux. Basically, it will be stuck at whatever speed it booted at (600Mhz for battery, full speed for AC.)