Re: Searching Tool for CPU stepping down
On Thu, Jul 27, 2006 at 07:14:00PM +0200, Hans-J. Ullrich wrote: > today I have an unusual thouhgt: I am looking for a tool, which I want to > start on the notebook, when doing nothing. I do NOT mean powernowd, cpufreqd > or similar, which use the pins on the cpu to switch it down (on my AMD-Turion > to 800MHz) I am looking for a tool like those on windows in the early 486er > days: they were called "waterfall" or "raindrop" and could change the > cycle-rate from i.e. 100 MHz to 10 MHz. > > Does somebody know such a tool for linux ? Or is this on modern cpus not more > needed ! You just described cpufreq. Just use a kernel with cpufreq support and use the "ondemand" or "conservative" governor to let the CPU switch to various frequencies. Note that you can't decrease the clock frequency on a 486 without extensive hardware support on the motherboard. Some 486 notebooks had such hardware (my old Digital notebook, for example), but the programming interface was non-standard: the Digital tools certainly didn't work on Compaq notebooks. > I imagine, with these tools, power would last much longer, when I can bring > my > processor down to 100MHz. > > Or do I think wrong Yes and no. Subtle detail: you don't want to save power, you want to save *energy*. See my OLS 2002 CPUfreq paper: http://www.lartmaker.nl/projects/scaling/cpufreq.ps.gz Erik -- +-- Erik Mouw -- www.harddisk-recovery.com -- +31 70 370 12 90 -- | Lab address: Delftechpark 26, 2628 XH, Delft, The Netherlands -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
Re: Searching Tool for CPU stepping down
On Thu, Jul 27, 2006 at 07:14:00PM +0200, Hans-J. Ullrich wrote: > Hi all, > today I have an unusual thouhgt: I am looking for a tool, which I want to > start on the notebook, when doing nothing. I do NOT mean powernowd, cpufreqd > or similar, which use the pins on the cpu to switch it down (on my AMD-Turion > to 800MHz) I am looking for a tool like those on windows in the early 486er > days: they were called "waterfall" or "raindrop" and could change the > cycle-rate from i.e. 100 MHz to 10 MHz. Nothing could change the speed of a 486. There were programs which would run in the background and "waste" 90% of the cpu, making you program run at 10% speed. There are also programs that would run when the system was idle executing 'HLT' or similar, to make the cpu power down for a bit to make the system use less power when idle. Linux does this by default. > Does somebody know such a tool for linux ? Or is this on modern cpus not more > needed ! Modern processors can actually be slowed down unlike the old ones, and it is done through powernow/speedstep/acpi. > I imagine, with these tools, power would last much longer, when I can bring > my > processor down to 100MHz. You can't do that. I know AMD Athlon 64's usually have 3 speeds, with 800MHz being the lowest. I have seen 800, 1200, 2000 MHz for example. Lower speeds also run lower voltage which further helps reduce power use. It does require using powernow to do it though either through powernowd, cpufreqd, or the acpi interface to it. > Or do I think wrong I am sure of it. -- Len Sorensen -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
Searching Tool for CPU stepping down
Hi all, today I have an unusual thouhgt: I am looking for a tool, which I want to start on the notebook, when doing nothing. I do NOT mean powernowd, cpufreqd or similar, which use the pins on the cpu to switch it down (on my AMD-Turion to 800MHz) I am looking for a tool like those on windows in the early 486er days: they were called "waterfall" or "raindrop" and could change the cycle-rate from i.e. 100 MHz to 10 MHz. Does somebody know such a tool for linux ? Or is this on modern cpus not more needed ! I imagine, with these tools, power would last much longer, when I can bring my processor down to 100MHz. Or do I think wrong Best regards Hans -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
