Core 2 Duo T9400: Hotter than other C2Ds?

Hello all,

I'm doing some research on the C2D T9400 that's in my laptop and so far my findings indicate that generally, the T9400 runs hotter than other T-series CPUs - even those which are faster (which logically should be hotter, not cooler). Would other mobile Core 2 Duo/Core 2 Quad owners mind helping me verify this? Please post:

• Your CPU model and clock speed
• Idle temperature
• Load temperature
• Have you repasted your CPU?

For myself:
• T9400 2.53Ghz
• 55-65°C
• 85-95°C+
• No

Thanks!

 

This data would mean nothing unless you're all comparing the same laptop model. What laptop is your T9400 installed in?

 

MidnightSun is right, you'd have to compare in the same laptop as the cooling solutions are different between laptop models.

 

It's in a Dell Precision M4400, which is very similar to Latitude E6400s and E6500s.

I've tried googling for this sort of information but it's sparse at best.

 

Seems a bit hot overall to me, but without comparison data, hard to say.

Have you cleaned your vents lately?

 

The vents are very clean, nearly like new. There's a very thin layer of dust on the fan that I haven't cleaned, but I'm holding off on that until I have the machine taken apart for repasting. I'm thinking about changing CPUs, too - either to a different (hopefully cooler) T-series or a P-series (which should definitely be cooler).

 

undervolt it. Mine runs almost .20v under the norm at max speed. I definitely cooled my notebook.

 

My T9300's load temperature is • 55-65°C with stress testing overclocked. (acer 5920g, tweaked cooling)

EDIT: are you ABSOLUTELY sure your heatpipe hasn't sprung a leak (gone bad)?

 

How would I check? Without ripping it all apart (just removing the bottom panel) it looks fine.

 

compare the the temp of the heat pipe to the cpu temp or even the air coming out of the heat sink. if the cpu is at 80-80c and the air coming out is luke warm or is not HOT, there may be an issue,

 

You are going to damage that laptop.
I suggest the following asap

1. open it up and clean out all the dust
2. apply proper thermal grease to GPU and CPU after you remove ALL of the old crap with rubbing alcohol and Qtips
3. this makes a huge difference I have found (10-12C drop in temp), add a copper shim to the GPU
the thermal pads are useless, you can use them between a shim and the heatsink to fill a gap if you have too
4. apply thermal paste to both sides of everything (LIGHTLY apply)

This will take you about 2 hours if you never opened up your pc before.
Look for guides on google and videos
get sandwich bags and label everything as you remove makes it MUCH easier when assembling

If you don't do this your laptop is likely to die soon or suffer other issues due to the heat slowly but surely desoldering things.

Copper shims can be bought from ebay.
you need to know the size and thickness (gap)
when you screw things back do NOT crank down on the screws just snug things up
no shim needed on the CPU

 

I find copper shims work best when lapped since they have a sharp ridge along the outer edge.

 

Well, here's my experience with two T9400's (that I upgraded from quite a while ago) on the same machine - Elitebook 8530, same GPU and heatsink.

One T9400 ran a full 15 degrees hotter at load than the other. In prime95, it got to ~76-78, while the second chip would barely reach 63. I thought the temp sensor was broken at first, but no, it did feel cooler to the touch and when fully loading the GPU (on the same heatpipe) it ran noticeably cooler, too.

Another interesting thing - the hot T9400 could be undervolted to 0.9V, while the second one could only go to 0.95V. Both OEM chips from HP.

I guess it should be no surprise - the TDP varies between chips, so one chip could be a full 35W TDP, while the other could be 26W and it would still be sold as a 35W TDP chip (but it would run cooler, and faster in Core i' case)...

 

well no two chips are exactly the same.

 

Alright, well I have a tube of non-conductive thermal paste (Arctic MX-2) coming in 5-7 days, so I'll just avoid stressing the laptop until then.

After reading around, there are indeed reports of a sizable gap existing between the GPU and the heat pipe on M4400s, which could be a problem since the CPU and GPU are situated next to each other on the M4400's motherboard. Do you own an M4400 yourself?

cdoublejj, what do you mean by lapped?

Thanks guys, you've been great.

 

Lapping a heatsink or in your case copper shims is sanding them to make the surface as uniform as possible.

 

Oh ok. For the GPU, do I go like GPU --> Paste --> Shim --> Paste --> Heat pipe or is no paste necessary for the shim?

 

You are CORRECT!