On Sat, April 14, 2007 2:05 pm, DJA wrote: > Lan Barnes wrote: >> :'-( >> >> It'll run idle overnight with no problems, but when I load the CPU (top >> says 30%), it goes from 38 C to 68 C in about 4 minutes. >> >> I'm taking it back and making the case that the original diagnosis >> charge >> should still be in force. > > Everyone keeps assuming that the problem is related to hardware. It may > very well not be. Fan and Processor speed are controlled both at the > BIOS level, and by ACPI. Someone mentioned Sensors - Sensors cannot > write, it can only read temp and fan settings, and in fact is known to > interfere with ACPI (which can and /does/ manage fan/CPU/temp settings) > on some laptops. > > I don't remember if you have Windows running on the laptop, but if you > do, then a sure way to see if it's hardware vs. firmware/software, is to > see if it overheats in Windows. In fact you may have to install Windows > just to get a reliable diagnosis. Looking at hardware only is _not_ > going to give a definitive answer unless something is obviously broken. > > Keep in mind that laptop manufactures' BIOS writers seldom properly > follow ACPI and ACPICA (Intel) specs, so many models don't work as > expected when it comes to fan/CPU/heat management. In Linux, it's the > job of ACPI to compensate. It's a very tough whack-a-mole type problem. > But it's getting better fast. > > There are ways to read your laptop's temp trip points and their > associated fan speeds and CPU throttle points. Sometimes just upgrading > to a newer kernel can fix the problem. Sometimes just upgrading to a > newer kernel causes a problem. > > I've found it educational and helpful to follow the ACPI4Linux mailing > list as well as the one specific to ACPI for my laptop. You may want to > do the same. > > I don't recall what brand of laptop you have, but if you can identify > the maker of its motherboard, you may find there is an ACPI kernel > module specific to it. For instance, there are for Sony, IBM, Asus, and > I think MSI and Toshiba. Do a search in Dmesg or the Syslog and look for > any strings containing "ACPI". >
Wow! That makes sense. I just got it back after a second day of diagnostics. They DID run it under windoze for that and it DID complete a night of trouble-free CPU 100% running. They chacked the temp with an external thermometer (the laser kind -- gotta get one of those). All was well. Result -- No HW probs that they can see. I'm sitting here seeing it say it's at 30 C. If I push it, I'm betting it'll say 68 C. If it doesn't shut itself off, and if I believe it's really 30 - 40, do I care? That's a real question. -- Lan Barnes SCM Analyst Linux Guy Tcl/Tk Enthusiast Biodiesel Brewer -- [EMAIL PROTECTED] http://www.kernel-panic.org/cgi-bin/mailman/listinfo/kplug-list
