According to Intel the thermal reading available from the SMBus (which is what the above software reads) is in direct relation to the maximum thermal specifications for the processor.

"Thermal Sensor and Thermal Reference Byte The Intel Xeon processor has unique system management capabilities. One of these is the ability to monitor the processor's core temperature relative to a known maximum setting. The processor's Thermal Sensor outputs the current processor temperature and can be addressed via the System Management Bus (SMBus). A "thermal byte" (8-bits) of information can be read from the Thermal Sensor at any time. The thermal byte granularity is 1°C. The reading from the thermal sensor is then compared to the Thermal Reference Byte.

" "Thermal Specification: The thermal specification shown is the maximum case temperature at the maximum Thermal Design Power (TDP) value for that processor. It is measured at the geometric center on the topside of the processor integrated heat spreader."

I do have trust in Dell's ability to cool adequately, I am just trying to rule out a defect in my particular system.

Does anyone else have temperature readings in a similar dual quad core Precision 490 they would be willing to volunteer? Thanks!

Message Edited by jds580s on 04-10-2007 09:10 AM

Well I can see a valid reason for that. I have a 490 at work with two dual core 2.66Ghz cpu's so I'll run some of those programs and check and reread to see if that is idle temps or not you posted. Good info on the heat monitoring too thanks One thing I have noticed is Dell uses thermal pads rather than paste and if they were not installed (heat sink with pad) properly like if it was put on and removed and put back on it could move around or just get messed up and not cover great. That might be a place to check if you want to actively look at something. I'll try and get those comparisons for you today.
Ok a quick of the system using intel tat.exe to load up one core per cpu gets it to 85c and it just stays there and this is tjunction.
It gets pretty loud but not as loud as the fans can get.

You are not the first to ask for this type of utility from dell and won't be the last.
They just won't release such a tool for some unknown reason. Even if they did the BIOS could be made to over ride settings that would be too low or any other number of protections.

Message Edited by tphillips63 on 04-10-2007 05:51 PM

Thanks tphillips63!

I did some additional research and testing today
It does indeed seem to be severely inadequate airflow.

Since you have the 490 as well you know there is a slot for two 80mm fans in the back. I happened to have some laying around and was able to splice them into the floppy power connector which I wasn't using. They are just cheap commodity fans nothing special but now under full load for about a half hour the temperature reading has dropped from 65C before to 51C after. The front fan is certainly hefty enough to supply this amount of airflow, but for some reason refuses to speed up beyond it's "low" setting.

Thanks for the comment on the thermal pad. I ended up removing the heatsinks cleaning off all the old pad/paste or whatever and re-applying Arctic Silver 5 and re-seating the heatsinks. That perhaps took a degree off of the readings but nothing that couldn't be written off as within a margin of error.

Lastly I did some airflow tests
when the case is open: no difference
when the case is open and the hard drive tray is swung out: approx 6C cooler

The Memory fan that hangs on the bottom of the hard drive tray directly blocks the exhaust airflow from the CPUs. Perhaps 30% or so of the total airflow is getting blocked. Also my Memory fan has a rubbery fin on the back side which apparently is to force air down in between sticks of ram. Seems like a good idea but it too blocks a good amount of air from flowing freely across the CPUs and out the back.

Now that I have the 80mm's in the back I am satisfied that the temps are OK even if there is no way to up the front fans speed. I tried a mod that suggested crossing the yellow and blue wire (the RMP & Control) which would force it to be on High all the time, but that didn't work and returned a front fan error on boot.

Thanks again for being willing to run those temp tests.

Found some good news!

There is a fan control program available here http://www.diefer.de/i8kfan/
It allows you to set the fan speed to Off, Low or High.

In my tests there is no difference between Low and Off on the Precision 490, both spin the fans at low speed. "High" however does turn the fans much faster than I was getting before doing this.

i8kfan also lets you set profiles that will kick the fans to high and low at preset temperatures.

Fan 1 is the front CPU fan
Fan 2 is the memory fan
(you can re-label these in the options menu to Front and Memory if you like)

Fan speed monitoring seems to work, although it didn't at first
Front Fan Off: 697 RPM
Front Fan Low: 700 RPM
Front Fan High: 1490 RPM

Memory Fan Off: 1086 RPM
Memory Fan Low: 1086 RPM
Memory Fan High: 2177 RPM

The software will also run at startup and display the temp in the system tray (unfortunately just one temp not one for each core)

Now the results!
Precision 490 Dual CPU Quad Core Xeon E5320's
Rendering 100% CPU Load measurement taken after about 30min
Stock: 65C
Stock with Arctic Silver 5: 64C
With 2 extra 80mm fans: 51C
With Fans on High and 2x 80mm fans: 47C

I doubt I even need the 80mm's any more but will keep them in there anyway.

A big thanks to Michael Henze (michaelhenze on the forums) for making this available to all.

That program is awesome. I have seen many posts asking for this and no mentions so far about it. I will rerun my tests with the program and see what happens. I like the small size of the 490 but it does seem to be too many hot things in a small area.

That doesn't work on mine. When I tried to boot with the side off it gave the error "Thermal Solution Compromised" and refused to go any further.

You are correct Lester67

I did my thermal tests yesterday morning with the case open which is when I ran into that error. Then in the afternoon I updated to the A03 BIOS. Today it behaves just like you said if I boot it with the door off. Neat Trick!

The fan speed I am getting with the door removed>boot>door closed is even higher than the "High" setting with the i8kfan utility

It's returning RPM's of:
Front Fan: 2521 RPM
Memory Fan: 3590 RPM

So the utility is good for a low and medium fan speed, you can get High speed by booting with the door off, not the most refined solutions but it works for me!

If you boot with the door open but have I8kfan set to override the default settings on startup it will slow the fans down, so to get high speed you need to first set it to only display fan info not control them, then shutdown open the door reboot close the door and the fans will be on full blast.

With the full blast fans I had my temps down to 22C (not under load though). That's such an improvement from where I was at yesterday morning.

Message Edited by tphillips63 on 04-12-2007 10:12 AM