Subject: Re: Driver for AMD K7 POWERNOW
To: None <>
From: Sergio Jimenez <>
List: port-i386
Date: 07/12/2004 20:14:42
>I have written a driver for AMD's POWERNOW function on K7 CPUs. It
>enables CPU frequency scaling which allows laptops with AMD K7 CPUs to
>have longer battery life and stay cool.
>I have made it compatible to i386/est.c (Intel SpeedStep) sysctl's

After a little work to apply the patch successfully, it seems to be
working. I've compiled a kernel using the max and min frequencies
allowed by my laptop and the times are quite differents:

- 500MHz

	# time ./ kernel=GENERIC
	1760.88s real 1594.39s user 175.95s system

- 1400MHz
	# time ./ kernel=GENERIC
	777.60s real 654.42s user 125.30s system

* After the first built I rebooted the box.

- Machine:

Acer Aspire 1300
mobile AMD Athlon XP 1600+
machdep.powernow.frequency.available = 500 600 700 900 1000 1100 1200

The lastest bios revision (3A71) for this serie from Acer has a bogus pst table
and less frequencies are allowed.

Thanks for the patch :)