i5 750 core temp 89-99C

[DeepJR]

Hello, I am looking to understand some discrepancies in 3 cpu temperature readings and advice on how to proceed given their dangerously high levels. I've included some recent history of the system.

Core Temp 1.0 and Speccy both show ridiculously high core temps over 90C. My ASUSTek P7P55 LX (LGA1156) BIOS (under Power--> HW) says cpu temp is only 78-79C.

I realize even if the lower reading from the BIOS is correct these temperatures are unacceptably high, but is it possible all 3 readings are incorrect? I get the same readings immediately after booting from a 30 minute power-off, and the core temperature doesn't decrease even when I am just running windows and normal background processes (I tried this for about half an hour).

Possibly relevant system history:
System was assembled 2.33 years ago. I haven't used this computer in over 2 months. 4 months ago I removed the processor from the mobo and packed it in a static-shielding bag for air travel (box+mobo were checked, processor and other components carry-on). When I reassembled at my destination (still 4 months ago) the thermal coating had dried onto both the heat sink (Intel E41759-002) and top of the processor. The system seemed to function normally (although I didn't take any temp readings) for 2 months up until I flew back home, this time keeping the cpu on the mobo but still removing the heatsink (Intel E41759-002)). I reassembled the box yesterday and everything was functioning normally, I only noticed the core temp because I was using Speccy to discover unrelated system information.

Pictures of contact surfaces of heatsink and CPU:
https://imageshack.us/photo/my-images/855/img01691.jpg/
https://imageshack.us/photo/my-images/560/img01671w.jpg/
https://imageshack.us/photo/my-images/826/img01681l.jpg/
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System Information (more detail here):
CPU: Intel Core i5 750 @ 2.67GHz
RAM: 4 GB DD3
Mobo: ASUSTek P7P55 LX LGA1156
GPU: 2x ASUS EAH4870
Power Supply: TX650w Corsair
Heatsink: Intel E41759-002

I am new here so apologies if this is the wrong place or format for this kind of post.

 

[DeepJR]

Edited OP with pics of thermal resin on heatsink and CPU:
https://imageshack.us/photo/my-images/855/img01691.jpg/
https://imageshack.us/photo/my-images/560/img01671w.jpg/
https://imageshack.us/photo/my-images/826/img01681l.jpg/

 

[DeepJR]

I have some thermal paste arriving in 3 days. I would still like to know what could be causing the different temperature reading between the software and BIOS, as well as what else I may be doing wrong to overheat the cores (I doubt new thermal paste will reduce the heat by 50C by itself).

Is it safe to run my system before I replace the thermal compound? Is it safe to run the system after removing the old thermal compound using metal-metal contact b/w heatsink and processor while I wait for the new compound to arrive?

 

[fireqce]

This is my i5-750 experience. Bios at iddle shows 53 C, with default heatsink and fan controll off /means always on full spin/ Windows 7 reports 64 C through intel core series widget when idle, at full load reports 100-110 C, bios warnings are enabled at 70 C, i have to push my system hard to get bios cpu temperature warning /so 110C in w7 is 70C in bios/. Maybe one of motherboard updates caused this. Motherboard: Gigabyte P55-UD4... my system ran for 3 years almost 24/7 with GPU and CPU computing enabled. This must be software or driver related issue. It seems that i5-750 have pretty good endurance when pushing to the limits.

Update: i realized that temperature measurement in intel core series gadget in w7 is dependant on proper TjMax setting, so in user manual to i5-750 there was TjMax 72,7 C, i have had TjMax 127 C so the measurements were all wrong. I have had to enter the proper TjMax values into the gadget.