EST (Enhanced Intel SpeedStep(R) Technology) on amd64
Alexander Motin
mav at mavhome.dp.ua
Fri Jan 9 01:51:33 PST 2009
Gabriel Lavoie wrote:
> I recently built a small home server using an Inten 45nm E5200 @
> 2.5 GHz. With FreeBSD 7.0, the "est" driver had problems pooling for
> the CPU frequency/voltage pairs and automatically disabled itself. It
> left the CPU at the frequency the BIOS put it after startup, 1.25 GHz
> because I have EIST enabled. I had to manually change the frequency or
> use powerd to put it at maximum. Now I upgraded to FreeBSD 7.1 and
> everything in my systems seems supported correctly. The est driver now
> recognize the CPU and load the correct information. Also, after
> bootup, the frequency of the CPU is at max (2.5 GHz). What I would
> like is to get the behaviour of EIST found under Windows and Linux
> where the CPU is automatically downclocked to 1.25 GHz when the system
> isn't under any load, but comes back to 2.5 GHz as soon as there is
> some load. I also get this behaviour under Linux on my Core 2 Duo and
> I really like it. What I found interesting is that it seems the Intel
> 45nm CPUs use under 5W of power when they are idle and EIST
> downclocked them. I would really like to take profit of this low power
> consumption. I found about "estctrl" on this page
> http://www.daemonology.net/freebsd-est/ but it seems outdated and when
> I try to build the port, it tells me that it is only supported on the
> i386 architecture. Why not amd64?
man powerd?
--
Alexander Motin
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