Sla#s said:
No, honestly it's designed to get that hot!
See the Pentium M specification at:
http://www.intel.com/support/processors/mobile/pm/sb/cs-007971.htm
Most other chips are limited to between 60 and 75.
A bit more research though has revealed that although the Pentium M can
get to 100 degrees the LV-675 motherboard is limited to 60!
I will have to find some way of silently cooling the other chips on the
motherboard - I am currently looking at some small heatsinks that can be
glued to the small chips on it. I will have to hope the heat pipe system
on the CPU keeps too much heat from going down into the board.
What I don't get is why a 100 degree chip is fitted to a 60 degree board!
It's like making a fireplace out of newspaper!
Slatts
You got that number from the datasheet on the Commell site.
ftp://ftp.commell.com.tw/Public/Datasheet/SBC/LV-675.pdf
"Operating within 0~60 centigrade"
That is an ambient temperature spec, for the air around
the motherboard. Such a spec might still make some assumptions
about cooling, such as so many LFM (linear feet per minute) across
the surface of the motherboard or whatever. That is not the melting point
of the socket material.
I went to the Pentium-M portion of the Intel site.
http://developer.intel.com/design/mobile/pentiumm/documentation.htm
This one looks interesting. It is Intel's instructions to companies
providing sockets. Page 36 lists the operating range for the socket,
of 0C to 105C, presumably consistent with a laptop kind of application.
"Intel Mobile Processor Micro-FCPGA Socket (mPGA479M) Design Guidelines"
http://developer.intel.com/design/mobile/applnots/298520.htm
If you look at the socket, it may have a manufacturer name on it,
like Foxconn or Lopes. You may be able to track down what they spec
for the operating temperature range for the socket. You'd need a
part number off the socket, if one is visible.
In my mind, it still remains a puzzle, where 68C comes from.
The processor datasheet itself, provides more thermal info.
THERMTRIP, which is the hardware protection feature that shuts
off the power supply, is set to 125C on the Pentium M 90nm.
THERMTRIP uses a diode on the processor die, and is managed
by the processor itself. The board designer connects it into
the logic chain that controls PS_ON#, on the ATX power connector,
and that is how the supply gets shut off on an overheat.
PROCHOT, the throttling temperature, is set at 100C Tjunction.
The internal instruction execution rate is reduced if that
point is hit, and performance drops. THERMTRIP should
only be needed, if the heatsink falls off or fan stalls.
Normally, throttling would be enough to prevent the temp
from shooting higher than 100C.
So your 68C number remains a puzzle to me, unless the actual spec
for the socket material, is inferior to the Intel suggested 105C
number. But 105C is needed for things like laptop applications,
so I don't see a point in cutting corners. With a throttle temp
of 100C, it looks like the socket and processor were designed
for each other.
I'd contact Commell tech support and see if they have an
answer to the puzzle.
Paul
