ATHCOOL - reference manual online

Control power-saving mode on AMD Athlon/Duron CPUs.

Jul. 27, 2004
ATHCOOL(8)                           System Manager's Manual                           ATHCOOL(8)

NAME athcool - control power-saving mode on AMD Athlon/Duron CPUs
SYNOPSIS athcool command
DESCRIPTION athcool is a program that controls the power-saving mode on AMD Athlon/Duron CPUs. The parameter command is one of: on Enable power-saving mode. off Disable power-saving mode. stat Query power-saving mode. list List supported chipsets.
WARNINGS athcool only sets/unsets the "Disconnect enable when STPGNT detected" bit in the north‐ bridge of the chipset. To save power, someone has to send the STPGNT signal when the CPU is idle. This is done by the ACPI subsystem when the C2 state is entered. Hence, you need ACPI support in your kernel to achieve power savings. Depending on your motherboard and/or hardware components, enabling power-saving mode may cause: * noisy or distorted sound playback, * a slowdown in disk performance, * system freezes or instability, * massive corruption of the filesystem (rare, but observed at least once). Before use athcool, you must recognize these potential DANGERS. Please use athcool AT YOUR OWN RISK. athcool is supplied "as is". The author disclaims all warranties, expressed or implied. The author and any other persons assume no liability for damages, direct or consequential, which may result from the use of athcool.
AUTHOR Copyright (C) 2002-2004 Osamu Kayasono <> This manual page was written by Nicolas Boullis <>. And many users reported to me it works (or not). Thanks to all who contributed to athcool. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either ver‐ sion 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. On Debian systems, the complete text of the GNU General Public License can be found in /usr/share/common-licenses/GPL.
SEE ALSO For more information about power-saving with Athlon/Duron CPUs, see the Athlon-Powersav‐ ing-HOWTO at
Jul. 27, 2004 ATHCOOL(8)