Windows 7 - bios temp / real temp

scrooge · 10-29-2010

hello
can someone please tell me why my bios temp is 31C. and after booting to windows 7 real temp says 42c.?
i'm using a E8400 chip and asus motherboard (p5q pro turbo) . what should the tjmax in real temp be set to i have it at 95 now .
thanks for your help
scrooge

A Guy · 10-29-2010

I believe it is because BIOS doesn't measure the core temps like Real Temp does. It measures the CPU temp. I think CPU temp will always be lower than the core temps? Also, differences in programs will do that. Intel said that Tjmax was 100, but they also said these sensors are incredibly inaccurate and get worse the further you go from Tjmax.

The RealTemp documentation outlines how you can calibrate your sensors to get more accurate idle temps.

A Guy

tw33k · 10-30-2010

My core temps are always around 10c lower than my CPU surface temp.

What are you're Cpu and System Temps ?

Bill2 · 10-30-2010

This is a somewhat hazy area but may be a intel/amd thing. On intel processors, core temps are reported higher than cpu temps while on amd's (at least certain amd's) its the reverse. Starting with the Phenoms, AMD's sensor no longer reports an absolute temperature anymore, but a reading with a certain offset, which is unknown. It is estimated that this offset is between 10 - 15c.

Also different motherboards have sensors placed somewhat differently.

tw33k · 10-30-2010

Quote: Originally Posted by Bill2

This is a somewhat hazy area but may be a intel/amd thing. On intel processors, core temps are reported higher than cpu temps while on amd's (at least certain amd's) its the reverse. Starting with the Phenoms, AMD's sensor no longer reports an absolute temperature anymore, but a reading with a certain offset, which is unknown. It is estimated that this offset is between 10 - 15c.

Also different motherboards have sensors placed somewhat differently.

That's right. For AMD CPUs, the CPU temp is taken directly from the mobo sensor. The Core temps are calculated readings based on who knows what (???)

HammerHead · 10-30-2010

Interesting subject. Only familiar with Intel. Core temps run about 8 -- 10 deg higher than CPU temp. I am trying to imagine why "core" temps would run lower. If the word core can be related to inside then they would run warmer as the skin is losing heat at a faster rate. I am going to have find something to read on that. I had never gave it much thought.

HammerHead · 10-30-2010

After some reading on the I7 900 series. It seems to me there is only one DTS on board the chip. A single wire (Trace) and a dedicated pin for output. The signal is analog converted to digital. I guess all the core readings, etc. are "voodoo" determined by some math calc.

AMD could be reporting the distance to Tmax which would give a lower reading than skin?

Pusspa · 10-30-2010

could the reason for the difference in temperature simply be that the computer is not under any load in bios, but after booting the OS, and the background process's running, there is a now a load?

LiquidSnak · 10-30-2010

Quote: Originally Posted by Bill2

This is a somewhat hazy area but may be a intel/amd thing. On intel processors, core temps are reported higher than cpu temps while on amd's (at least certain amd's) its the reverse. Starting with the Phenoms, AMD's sensor no longer reports an absolute temperature anymore, but a reading with a certain offset, which is unknown. It is estimated that this offset is between 10 - 15c.

Also different motherboards have sensors placed somewhat differently.

Could it just be a "Phenom"enon? (I'm sorry, I could not resist)

The AMD temperature reading could read lower, as the motherboard might absorb heat, while the cores are in direct contact with the case, which offers cooling?

linnemeyerhere · 11-04-2010

From my latest Intelligence it is a Phenomenon !