New motherboards often have a small fan covering one of the bridge chips. Likewise, expensive graphics cards have a fan on their processor. These fans are cheaply made.
Is there protection for the MB/card to keep their chips from frying if the tiny little fan fails?
TIA
On Sat, 12 Jun 2010 21:43:36 +0000, root ??o??:
No.
On Sat, 12 Jun 2010 22:13:51 +0000, Meat Plow ??o??:
I'll revise that and say that if said fan is monitored then there can be an audible alert set up if the fan drops below a certain RPM. The fan would need to have three wires to be monitored. Also in BIOS there should be a setting to alert if the mainboard goes over a set temperature limit. The default limits are usually good enough to use.
On most motherboards built today, there's a temperature sensor associated with the CPU (sometimes several e.g. individual temperature- sensing diodes in the CPU's cores) and others on the board. The sensor values can be read out (often via SMBUS) by the BIOS or other software.
Better motherboards use three-wire fans with tachometers, where the tach frequency can be read out of the sensor chip.
Modern BIOSes will usually let you set a temperature alarm, on a per-sensor basis, and arrange for some sort of emergency action if the temperature rises too high or the fan speed drops too low. The actions can involve slowing the CPU clock to reduce power consumption, sounding an audible alarm, triggering an OS shutdown, or (in extreme cases) just halting the processor(s).
Graphics cards could implement similar fail-safe mechanisms. I don't know if they do.
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Some motherboards have thermistors mounted under various chips and software included on the setup disk with temp monitor and alarm.
I think my other PC has it, but its not obvious - I'd have to re-run the setup disk to find out where it is.
Either that or I didn't bother with it last time I did a clean install.
"ian field" wrote in news:bTTQn.27090$g76.4060@hurricane:
often,before anything fries,you start seeing wierd things,glitches,freezes,etc.
maybe you could/should build a temp monitoring system,separate from the PC circuitry,with red LED's that flash when a zone goes overtemp,and voices "warning,warning" in a robotic voice ala Lost in Space.(use a speech chip from a greeting card...) it could even kick in an emergency backup fan,and perhaps even a freeze spray blast to chill things down.
[end "humor" mode]-- Jim Yanik jyanik at localnet dot com
I've yet to see a motherboard that did anything with the chipset fan speed data. You can run an application that'll monitor it, but almost nobody goes to the bother as most such applications, written for microsoft windows, were modeled to resemble someting out of a comic book and are an eyesore even when minimized. Linux' lmsensors doesn't require such an eyesore on the desktop, but is a bit of a PITA to set up.
The better motherboards either use a quality fan or a heatpipe to a heatsink cooled by the cpu fan.
On Sat, 12 Jun 2010 18:08:50 -0500, Jim Yanik ??o??:
Ummm not to spoil your humor however, there is/was a PCI card and front panel that did just that. Designed for those who used to overclock their systems and run them on the ragged edge.
On Sat, 12 Jun 2010 18:20:19 -0500, AZ Nomad ??o??:
For the most part decent mainboard provide enough surface area to their Northbridge chipset and onboard video to be passively cooled. The extreme end boards offer heatpipes and fancy servo fans.
I have a fanless NVIDIA based graphics card that I was running with inadequate ventilation. When used on graphics intensive tasks, it started behaving as if there was increasing fog in the scene being viewed. This would have reduced the amount of processing it needed to do. The GPU didn't fail, and this effect was apparently invisible to the software driving it. I infer that it was a designed response to excess temperature.
A fan cooled version with a failing fan would presumably do the same thing.
Sylvia.
Not necessarily true. THe chipset could easily have an over-temperature detection circuit built into the die. At least that's how I'd do it, since that would detect multiple problems that monitoring just the fan's rotation would not do. After all, a fan turning is not always a fan delivering power!
On Sun, 13 Jun 2010 08:35:38 -0400, PeterD ??o??:
No of course it's not necessarily true. I can't speak for every frigging manufacturer out there. Certainly both cases are true, MB temperature monitors and monitored fans and both. My MSI MB has a monitored rear
120mm fan and MB temperature monitoring. Most of the boards I've dealt with are Intel, Asus, and MSI. I can only recall one using a small fan on the pci bridge chip. The rest were equipped with a large heat sink. The emphasis on using one large fan in the rear to quietly exhaust inside air rather than having a bunch of small 5000 rpm fans making a racket.
Some do, most don't. Most machines require running applications software to monitor the cpu, mb, hd, fan speed, etc, which then initiates a shutdown. This is typical:
Other motherboards (some Dell's) have the monitor built into the BIOS. Most CPU's will protect themselves from overheating by slowing down the clock. Motherboards with this feature usually allow setting the overtemp alarm threshold. This is common in server BIOS's. If you see a "thermal event shutdown" in the BIOS log file, the computer was turned off automagically due to overheating or fan failure.
Intel provides various monitoring utilities:
You're correct to worry about the survivability of the little fans. Once they overheat, they melt. When they melt, they slow down or stop. You might have some luck tearing the fan apart and applying some oil, but that only lasts for a few weeks. Replacement is the only real option. If you want to keep your unspecified model motherboard fan alive, keep the dust and crud out. Breaking it loose with a paint brush, and blowing the case clean with an air compressor is my method.
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There is a cheap "Fan Alarm System" card available:
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