Need help with Speedfan readings please!

"System" should be the sensor in the Northbridge and 90C, IF ACCURATE, is dangerously high. And 98C(200F) is about the melting temp for the plastic chip case. Something expensive may be getting fried. Don't trust SpeedFan alone, check temps in your BIOS and see how they compare with Speedfan. If you see 90C in the BIOS shutdown and fix it ASAP.

If not overclocked, 90C would make me suspect the chipset or CPU heatsinks are not on right. Speedfan may have the labels reversed too. It could be the CPU that's hot. The BIOS temps should be more accurate.

You'll have to use a thermometer or your fingers to really find the problem. For the finger test, 90C will be too hot to touch. You'll want ice cubes handy to treat the burn.

If you really have a part running 90-98C I recommend you remove the MB, remove the cooler, clean off all the old thermal goo from both cooler & chip, and reinstall the cooler with new grease. Check both northbridge & CPU heatsinks, make sure they're tight. Careful with both coolers, if you break a pushpin you'll have to buy a new heatsink.

My software temperatures never seem to match my thermometer. On my Gigabyte P45 board the temperatures for System & CPU are switched around between Speedfan and HWmonitor and PCwizard.

I have a temperature probe in the heatsink fins of my Northbridge. It currently shows 40C (103F) and that matches what it feels like to my fingers. Speedfan and HWmonitor report system temperature between 20 and 30C. I trust the thermometer more than Speedfan or the BIOS.

The best way to check temps is to use a thermometer with a very slender probe that can fit between the heatsink fins like this Scythe TM02-BK on www.newegg.com/Product/Product.asp [...] 6811998047 or CompuNurse on www.coolerguys.com/thmo.html.