Re: What's an acceptable temp increase when overclocking?

In article <1%dLg.89092$du4.985575@xxxxxxxxxxxxxxxxxxxx>, "Phil"
<phil_essing@xxxxxxxxxxx> wrote:

Download CoreTemp and check your core temps. Each core has its own DTS
(Digital Thermal Sensor) located as close as possible to its hottest point.
These temps will be hotter than what you see in the BIOS or PRobe, as they
are read from a thermistor on the mobo, likely under the CPU socket. You'll
want to make sure your core temps stay below mid-70s.

http://www.xtremesystems.org/forums/showthread.php?t=103638

-phil

According to this, the DTS are on the silicon die of the processor.
There is no need for any thermistors in the processor socket area.

http://www.tomshardware.com/2006/07/14/core2_duo_knocks_out_athlon_64/page7.html

DTS measures relative temperature - a reading of -20C from the sensor
means the processor core is 20 degrees C away from the thermal throttle
point. A reading of 0C relative, means the processor core is so hot that
it is about to throttle. The job of any conversion program is two-fold.

1) Find the hardware support on the motherboard for DTS. I haven't
figured out yet, which chip holds this info. (At least the
Winbond chip that interfaces to DTS via the PECI pin, uses
the SMBUS.)
2) Compute Tcase_Max plus the DTS relative value, to get a true
die temperature. In reading the Intel data***, I don't see
an indication of how accurate this digital on-die sensor scheme
is. The Intel data*** claims the absolute temp measurement
capability only goes down to 30C, meaning people with phase change
cooling will be getting the DTS error code 8002 hex instead of a
temperature reading. For air or water cooled systems, DTS should
still work.

Conroe also has the normal thermal diode on its silicon die, which
a motherboard maker can connect to the hardware monitor interface
on the Super I/O chip. The Intel data*** says Conroe processors
do not include a correction factor for the thermal diode, like
previous processors did.

I would think any software tool reading the DTS, would be better
off just reporting the relative reading straight from the hardware.
A reading of -20C relative tells you that your processor is well
cooled. A reading of 0C relative tells you the processor is about
to throttle. So even the relative value, without any attempts
at calculation, would be better than nothing.

On this page, I can see Winbond has a hardware monitor chip
(W83793G) that sits on the SMBUS (yuck). It has a PECI input
on the chip, to get DTS readings from the processor.
Unfortunately, the data*** is not available for download.

http://www.winbond-usa.com/mambo/content/view/142/271/

ITE also makes a couple of chips that connect to the PECI
pin, and they claim +/- 1C accuracy. Again, no data***,
and no way to verify what claims they are making. The +/-
1C could be for the old thermal diode on the silicon die.

http://www.iteusa.com/ite_news/press2_20060512-1.asp

It is also possible a motherboard may not even have a PECI
readout chip, but just have something to fake out the
interface. To understand whether that is feasible, I'd need to
find more detail on PECI - the Intel processor data*** is
not too helpful.

Intel also keeps track of whether PECI works on a given
processor. Here is an example from the processorfinder
site, and says "These parts are PECI enabled":

http://processorfinder.intel.com/details.aspx?sspec=sl9s7

I think sticking a finger on the processor heatsink,
gives you more accurate info than all the fancy sensors :-)
All this extra complexity and for what purpose...
I guess the old diode sensor on the silicon die,
just wasn't enough fun.

Paul



"greysky" <greysky@xxxxxxxxxxxxx> wrote in message
news:Ga8Lg.24259$gY6.12800@xxxxxxxxxxxxxxxxxxxxxxxxxxxxx
I have a new system running a 2.4 GHz core 2 duo. Normally my cpu
temperature is under 39 C when running at stock speeds. When I run the FSB
at 420 MHz my cpu temp increases to 50 C. My question is what is
considered an acceptable temperature increase for these new Intel chips?
Should I back things down or is 50 C ok? TIA.


.