Why can GPU's get so much hotter than CPU's?

[Zebo]

They can't. Silicon melts @ 1400C for both. They both become unstable they higher temp you go. I can run a A64/C2D all day at 150C if the internal temp monitors wouldnt shut chip down, albeit at lower freqs to maintain stable, just like a GPU.

GPU's are downtuned to allow wider variances in core temps because of small slot coolers inherent problems is why you see them hitting 90C with little issue.

 

[ElFenix]

i accidentally left the fan unplugged on an athlon one day, and it crashed at about 85 degrees (didn't burn the chip, thankfully). my 1900 can get above that with perfect stability. so i'm going with the hot spot theory. though some other plausible sounding theories have been posted as well.

 

[eojinlim]

You have to manually set the throttle. On my 8800gts it states that it will throttle my core and memory at 120C. However, you really should take the initiative and set it a little lower like 90-95C.

Currently my 8800gts idles at 62-64 and at load (when using atitool's check for artifact) it is constant at 84C).

 

[thilanliyan]

Originally posted by: Gatt
Actually, the higher the temperature the more Silicon begins to conduct electricity. Silicon's semi-conductor properties decrease with heat.

This is true up to a point I think (ie. you can't go to like 1000 celcius and expect it to be an amazing conductor). I can't remember where the critical point is though. SOmeone correct me on this if I'm wrong.

However, it's the dopants that have the largest impact on conductivity in silicon....not really temperature.

 

[evolucion8]

I don't think it has something to do with clockspeed. A GPU tends to work harder and more parallel compared to a CPU, a Radeon X800XT which runs at 500MHz can do as many as 100 times more floating point calculations than a Pentium 4 3.0GHz, imagine a GeForce 8800GTX or Radeon X1950XTX what can do! For me is an enigma why GPU's are able to run hotter without problems and the CPU's don't. Pretty sure a C2D or My P4 can't run stable at 80C like my old Radeon does.

 

[Navid]

Originally posted by: thilan29

Originally posted by: Gatt
Actually, the higher the temperature the more Silicon begins to conduct electricity. Silicon's semi-conductor properties decrease with heat.

This is true up to a point I think (ie. you can't go to like 1000 celcius and expect it to be an amazing conductor). I can't remember where the critical point is though. SOmeone correct me on this if I'm wrong.

However, it's the dopants that have the largest impact on conductivity in silicon....not really temperature.

Pure (intrinsic) semiconductor alone is useless for making transistors. Its resistance is very high at room temperature.

Transistors (building elements of GPUs or CPUs) are made using semiconductor with added impurities (dopants). The conductivity of such a semiconductor (extrinsic) is comparable to that of metal.
http://en.wikipedia.org/wiki/Extrinsic_semiconductor

Temperature has the opposite effect on the conductivity of extrinsic semiconductor.
That is why the maximum operating frequency of a CPU goes down as temperature goes up.

 

[thilanliyan]

Originally posted by: Navid
Transistors (building elements of GPUs or CPUs) are made using semiconductor with added impurities (dopants). The conductivity of such a semiconductor (extrinsic) is comparable to that of metal.
http://en.wikipedia.org/wiki/Extrinsic_semiconductor

Temperature has the opposite effect on the conductivity of extrinsic semiconductor.
That is why the maximum operating frequency of a CPU goes down as temperature goes up.

Originally posted by: thilan29
However, it's the dopants that have the largest impact on conductivity in silicon....not really temperature.

 

[Navid]

Originally posted by: thilan29

Originally posted by: Navid
Transistors (building elements of GPUs or CPUs) are made using semiconductor with added impurities (dopants). The conductivity of such a semiconductor (extrinsic) is comparable to that of metal.
http://en.wikipedia.org/wiki/Extrinsic_semiconductor

Temperature has the opposite effect on the conductivity of extrinsic semiconductor.
That is why the maximum operating frequency of a CPU goes down as temperature goes up.

Originally posted by: thilan29
However, it's the dopants that have the largest impact on conductivity in silicon....not really temperature.

Temperature has a significant impact on the conductivity of silicon.