K8N Diamond Plus chip temperatures

Question

I do not have air conditioning, and with the arrival of summer I was having an apparent overheating problem, so I investigated further.  MSI CoreCenter showed CPU and Sytsem were fine (low 50's under load).  But when I started up the nVidia Monitor, my nForce chip was running high 70's.
The temperatures between CoreCenter and nVidia Monitor match well, and the nForce chip was darned hot to the touch, so I assume all the readings are reasonable.
The heat pipe appears to be working (the pipe is hot all the way up to the Zalman cooler, and there is a pretty good relationship between the System temp and the nForce temp - when nForce goes up the System temp also goes up).  There is about a 28C degree difference between the System temp and the nForce temp.  The little system fan on the MSI Zalman cooler modulates up and down to hold the 50C setpoint.
In summary, my system IDLES in an 30C room with:
CPU: 37C
System:  46C
nForce:  75C
That nForce temperature seems way too high to me.  Anyone else notice this?  Does it sound like something is wrong, or is this just the nature of the heat pipe solution on the nForce chip?
Thanks,
DJG
MSI Diamond Plus SLI x16 mobo  (MS-7220?)
AMD Athlon 64 x2 Dual Core 4200+  running at 2.5GHz w/ Zalman CNPS9500 cooler
4 x Kingston HyperX 512MB ram (2 Gig total)
Dual eVGA 7800GT video cards in SLI mode w/ Zalman VF-700 CU coolers
Antec 550W True Power 2.0 power supply
Creative x-Fi sound card
Cooler Master Centurion CAC-T05 case with upgraded fans
Envision Professional Series 20" LCD @ 1600x1200

Answer 1

I believe there is some confusion here caused by the SLIx16 capabilities of the Diamond Plus board.  Let me try to give a quick, non-technical explanation:
Back in the old days, there were three major chips on a board - the CPU, the Northbridge and the Southbridge.  The Northbridge handled memory addressing and the AGP bus.  The Southbridge handled most other communications (drives, serial port, etc...).  Then AMD put their memory controller on the CPU chip, and the need for the Northbridge went down.
With the later nForce chips, nVidia started producing a one-chip solution.  The Northbridge and the Southbridge were combined together in what became the nForce4 chip.  Now there were only two major chips on the motherboard - the CPU and the combined Northbridge/Southbridge nForce chip.  This was a a very popular solution, and so you saw a lot of motherboards and software and BIOS implementations that would only show two temperatures, the CPU and the SYSTEM.  That's also why you only see two cooling solutions on a lot of modern motherboards, something for the CPU and that little high speed fan mounted right over another chip - the nForce.
With the release of SLIx16 nVidia had to go back to a two chipset solution.  They probably ran out of pins or something, but they went back to the concept of a Northbridge (which handles one video card) and a Southbridge which handles the second video card and other communications).  This is what the MSI Diamond Plus motherboard implements.  So now there are three major chips on the motherboard again - the CPU, the Southbridge and the Nortbridge.  But, since lots of software and BIOS implmentations altready existed that only showed only two temperatures they just stole the software and the naming.  So the Southbridge chip became labeled as the System chip (and of course the CPU was still labeled as the CPU).  But they have not added the Northbridge temperature to tools like CoreCenter (CoreCell?) or the BIOS.
That's also why on the Diamond Plus board you've got three heatsinks - one for the CPU, a heatsink with a heatpipe (the low profile chip underneath the video cards, with that stamped silver MSI label on it) for the Northbirdge nForce chip, and a Zalman copper heat exchanger over the System (Southbridge) chip.
The nVidia nTune version 5+ tool will reveal all three temperatures - the CPU, the System (Southbridge) and the nForce (Northbridge).
This thread is about the temperature of the Northbridge chip.  Again, the standard tools of CoreCenter and BIOS do NOT show its temperature.  But the nTune 5+ version does.  On my board, both the CPU and the System (Southbridge) chips are running perfectly acceptable temperatures.  But the nForce (Northbridge) chip is idling in the 70C+ range.
I'm trying to see if other people's Diamond Plus board are also seeing those temperatures.  If you do not have a Diamond Plus board, this may not make much sense.  But it is something I am worried about.
Thanks, and hope this helps clear up any confusion.
DJG