From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Thu, 18 May 2000 16:33:42 +0200 From: Sven LUTHER To: "Timothy A. Seufert" Cc: luther@dpt-info.u-strasbg.fr, Michael Schmitz , Albrecht Dreß , Tim Wojtulewicz , linuxppc-dev@lists.linuxppc.org, debian-powerpc@lists.debian.org Subject: Re: Pismo status Message-ID: <20000518163342.A14744@lambda.u-strasbg.fr> Reply-To: luther@dpt-info.u-strasbg.fr References: <39226066.BF822A70@mpifr-bonn.mpg.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: ; from tas@mindspring.com on Wed, May 17, 2000 at 10:15:24PM -0700 Sender: owner-linuxppc-dev@lists.linuxppc.org List-Id: On Wed, May 17, 2000 at 10:15:24PM -0700, Timothy A. Seufert wrote: > At 2:08 PM +0200 5/17/00, Sven LUTHER wrote: > >On Wed, May 17, 2000 at 12:54:22PM +0200, Michael Schmitz wrote: > >> > Tim Wojtulewicz wrote: > >> > > No it's definitely supposed to have a fan. It comes on in MacOS. > >> > > The problem is that the PMU is not fully supported yet, so it doesn't > >> > > understand that the processor is too hot. I'm trying to find > >> > ^^^^^^^^^^^^^^^^^^^^ > >> > Does this mean that I can damage the machine if I just run a high-load > >> > program?!? > >> > >> I strongly doubt that. The PMU should handle this autonomously, regardless > >> of Linux support for the PMU. > > > >Also, i think the ppc cpu will halt itself when becoming too hot, > > No, it will not. > > The PowerPC 750 (G3) and 7400 (G4) can both fire off an interrupt > when the on-die temperature sensor reading rises above a trigger > value (or falls below a second trigger value). This feature *could* > be used by an operating system to slow down the CPU (through the So this mean that the G3 and G4 cpus have both the equivalent of speedstep/whatever that AMD & Intel are introducing as a big novelty ? > instruction cache throttling feature) or halt it to prevent > overheating. However, there is no hardware feature which can halt > the CPU without software control. Are you sure about this ? did you already manage to burn out a ppc cpu like you do when running a pentium without a fan ? > > and not let > >itself burn. At elast it was so since the earlier 680x0 cpus. > > As far as I know none of the 680x0 CPUs even had an on-die > temperature sensor, let alone a thermal shutdown feature. I think to remember that the later 680X0 have, maybe not a temperature sensor, but a way to halt themself before burning, ... Friendly, Sven LUTHER ** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/