Dell Latitude E6400 heatsink

Since the GPU and CPU share the same cooling system, the added heat from your T9600 could be raising your GPU temps. 65C idle is nonetheless somewhat warm, specially for such a low ambient.

You know, I've never figured out how the fan speed thing really works. Originally I thought it would turn on whenever the GPU hit 60 and turn off whenever it went back down below 50... but lately it's been doing 55 to 47 or odd numbers like that. I've been leaving my HWMonitor running pretty much all the time, but I'm not really finding any sort of pattern. The fan runs some of the time, but always at the lowest speed. When it first kicks in, it'll run up to full speed, then taper off.

The D830 DOES have two heatpipes, but there is still a thermal pad under the second heatpipe. The gap between the second heatpipe and the GPU on the D830 is actually LARGER than the gap between the single heatpipe and the GPU on the E6400. You need two copper shims for a D8300 copper mod and only one for an E6400 copper mod.

The overall TDP on the D830 and D630 should be higher than the overall TDP on the E6400 and E6500, hence the extra heatpipes and whatnot. I do believe that most lower-power Dells (yes, I count E6400 and E6500 count as lower-power systems) have single heatpipe thermal solutions right now.

Stock temps were generally higher on my D830, but the stock GPU temp never went past the mid-eighties at load. Not quite sure why that is considering the higher TDP of the NVS140 and the thicker thermal pad under the heatsink. That second heatpipe probably helps more than I think.

 

After studying temperatures and fan speeds a lot on my E6400 I am quite sure the NB/chipset temperature is what is mostly causing the fan to run. The fan starts at low speed when the chipset temperature reaches 45-46C and stops when the temperature has dropped to 42C. If the chipset temperature reaches 50C the fan will go full speed. Also if the CPU is very hot it will trigger the fan. In your case with discrete graphics the GPU temperature will probably affect the fan speed a lot. The fan logic seems to have been consistent in BIOS A09 and A11 but some people report that it might have been different in earlier releases.

BTW, the Latitude E6500 seems to have a separate, properly attached heatsink for the GPU. See http://support.euro.dell.com/support/edocs/systems/late6500/en/sm/html/cpucool.htm

Örjan

 

It could, but i don't think the CPU temps would affect the GPU temp very much. While my GPU temp was in the 60s, my CPU temp was in the mid 30s.
I haven't removed the thermal pads (only the cooling unit as a whole), but i am thinking of tearing them out and just add AS5 as seen here with an old Asus laptop.

Yes, I believe the fans are not linking to the CPU temps. Most laptops have their fans run according to the CPU/chipset temps. With my GPU temps being so high on idle, my fans are super quite. It's only when i start running intensive tasks that raise my CPU temp do the fans start to kick in.

On a side note, I recently found out that like many computer manufactures, Dell has started to cut corners to save on cost. A copper plate would cost Dell an extra $0.15 per laptop, and these costs add up when they are sold in hundreds of thousands, if not millions.

 

Ah, your BIOS revision might explain the discrepancy in fan activity. I'm still using A01 as I've heard that the later BIOS revisions run the fan more often. My NB temps are regularly in the mid-fifties with the fan off, upper-forties with the fan on.

The E6500 probably has the second heatpipe in anticipation for the warmer GPU used in the M4400. Or maybe it has something to do with the more central location of the GPU.

You'll probably need a copper shim. The heatsink (or at least mine) won't make contact with the GPU without the thermal pad. You should also save the thermal pad (scrape it off carefully with a hobby knife) in case something goes wrong.

 

Thanks a lot for this information. I am tempted to downgrade my BIOS to see if it makes any difference for the fan. There have been a lot of bugs fixed in later BIOS versions according to the download page. Are you not affected by these bugs?

I have an open support case with Dell regarding the fan logic. I am trying to convince them to change the fan logic in BIOS or replace the chipset heatsink in my laptop if there is a newer revision of the heatsink assembly available. So far I have not been successful but I will not give up yet.

Örjan

 

What kind of bugs are we talking about? I haven't been keeping up with the recent BIOS updates. I've had two or three BSoDs on my E6400, but they've all been of the driver irq flavor, so I've never thought much of it. Do tell if you make any progress on your support case though; I'd love to have a perfectly silent E6400

 

Here's the info I found on some of the BIOS

A02
1. Added support for Service motherboards.
2. Improved EC handling of internal keyboard.

A03
1. Added support for Intel(R) vPro(TM) configurations.
2. Fixed issue where USB PowerShare might keep a device powered when entering Standby.
3. Improved the discharge algorithm for systems with two batteries.
4. Added SMBIOS support for reading/writing Password Changes option.

The BIOS release has been validated on the following operating systems:
1. Microsoft Windows Vista
2. Microsoft Windows XP Service Pack 3

A06
1. Added support for Intel(R) vPro(TM) configurations.
2. Fixed issue where USB PowerShare might keep a device powered when entering Standby.
3. Improved the discharge algorithm for systems with two batteries.
4. Added SMBIOS support for reading/writing Password Changes option.

A09
1. Added support for BIOS that is signed.
2. Updated to PSA build 4117.
3. Fixed the issue where system is slow to boot to internal hard drive after failed PXE boot exits.
4. Fixed the issue where Some BIOS Setup parameters are not accessible with only the keyboard.
5. Fixed the issue where system will automatically shut down at resuming from S3.
6. Fixed the issue where the time of BIOS power event log in Setup is wrong for power button event.
7. Fixed the issue where presentation mode cannot be turned on/off from the DCP.

A11
1. Fixed issue where Intel(R) vPro(TM)-configured systems may
erroneously shutoff in some situations due to a false overtemp
condition.

 

I have now tried all BIOS versions that are available for download from DELL: A11, A09, A06, A03 and A02. They seem to be the same regarding the full speed fan mode. With any of these BIOS versions, the fan starts running at full speed (4800 RPM) when the chipset temperature reaches 50 C. Maybe version A01 is different, but since it is not available for download I cannot test it.

I will keep my support case with Dell open until they do something about this.

Örjann

 

Orjan, what program are you using to monitor your rpm fan speed?

 

call me a noob, but i think i just found out what my problem was.
Apparently I had too many devices plugged in my Dell. Monitor, printer, external mouse + keyboard, external optical drive, camera and iphone. Without any of these devices plugged in, my idle temps are now 54C.