Can the bios report the wrong CPU temp?

simple thing can the BIOS report the wrong temp for a CPU? the BIOS is reporting 65C 145F but when i put a blue point infrared temp gun to the heat sink it says 95F.. This is on my back up computer with a AMD Athlon 2700. Now when i put the temp gun to my main computer 775 2.8ghz HT it reads around 90F on the heatsink while the Bios reports 95F for the CPU a 5* difference so am i right in thinking that the Bios is reporting the wrong temp on the back up rig?

This is the mainboard out the backup
http://www.pcstats.com/articleview.cfm?articleID=1342

CPU
http://www.oldcpu.cz/CPU/AMD/Athlon-XP/AMD-AthlonXP-AXDA2700-DKV3D

 

Sure, temps sensors used to be pretty iffy. You have to be the first I've ever seen with IR gun though. That is geeky to the hilt!:-D The sensor is inside the chip so it be hotter there, all depends on if you're comparing apples to apples.

 

You know you have a PM right? lol I got the IR gun from a friend there not cheap they use it on there race car at the trackfor tires and such its made by Snap-On when i noticed that about the temp i thought thats just what i needed lol

 

Frankly using the gun on the HS is not going to give you a true indicating temp of the CPU. The reference point is on the "base" of the HS and coming from the IHS of the CPU. Your 1/2 way up the HS "cycle" at best and a large % of heat has already dispersed, transferred and or distributed. You should compare the BIOS reading with either of these in OS apps and see if they compare:
EVEREST Free Edition 2.20
Real Temp
Core Temp 0.99.5

You need to be taking the heat reading from as "close to the source" as possible and unless you are going to drill a small hole near the base of the HS and point the laser in there your not going to get anything "slightly" accurate using that. Have a look at some LN2 or CO2 HS (pots) and look at where they put the sensors for the extreme cooling of CPU runs, it is right near the "contact surface"!!!

The BIOS is more accurate in this case!!!!

Using it on tyres is fine because that is the "point of contact" you wouldn't be taking it from the wheel rim and making an inference into tyre heat?!?

 

The Real Temp website says it's for Intel processors. Also, CoreTemp states a list for AMD which only shows processors newer than the Athlon XP series, which I presume is what N5638J has. IOW, he has an Athon XP 2700. Right, N5638J?

I have an Athlon XP 2200 and use SpeedFan, which gives me a reading consistent with what the BIOS shows if I access the BIOS and view the temp there. This is with an ECS K7S5A PRO motherboard.

 

that temp reading was at the base where the heat sink meets the processor... Thanks for the advice its help. Well started all this was it was running fine and windows got a problem messing around with settings and while i was running down leads i seen that the temp was not like it use to be and thought the sensor just went bad because i have had no trouble with it being stable or smells or anything.

 

Good point an oversight on my behalf.

Well even pointing at the base will not give any "reliable" or accurate reading. Here is a LN2 pot and you can note a hole down near the base where the wire is inserted for the sensor probe. The wire is inserted to ~ the middle of the contact point and gives an "indication" of cpu temp:

http://www.koolance.com/water-cooling/product_info.php?product_id=832

If you look at the additional pics the sensor will be were the central core has tapered to it's finest point.

 

Just a update thanks again for the info.. The Bio's started reading the right temp again the same as what the IR gun stated just afew *'s off..