Z61p (GPU?) overheating

[smomma]

It is your wisdom regarding overheating problems that I need to dip into this time.

I got a Z61p (9453-CTG) for my daughter, put a 32bit Ubuntu 12.04 on it, and it works quite well for her.
With one exception: as soon as there is significant graphics card activity, the machine gets very hot, and even shuts down spontaneously after a while. (A second machine that I keep around for replacement shows the same behaviour).

xsensors reports temperatures above 80°C (not good ...) on sensor 4 (which I think is the sensor next to the GPU (a Mobility FireGL V5200, if I interpret the lshw output correctly).

I then installed Thinkpad fan Control (together with tpfacn-admin) and configured it to increase the fan speed when sensor 4 goes beyond 70°C.

Unfortunately, the fan allows speed regulation only in a very coarse way.
speed state 7 (called "100%" in tpfan-admin) is at just below 3100 rpm. This is just barely enough to keep the temperature at just about 70-72 °C. The fan is distinctly audible at that speed, but not yet annoyingly so.
Beyond that the only other setting is "disengaged", which causes the fan to roar at about 4800 rpm, at a noise level that is really annoying (and not university library compatible ...).

Trying to find a remedy for this, I read about several options:
Software:
- undervolting the machine -- from what I found so far, that only seems to affect the CPU, not the GPU -- please correct me if I'm wrong here.
Hardware:
- taking apart the machine, pulling out the GPU and replacing the thermal paste (is that the correct term?) with fresh one, because it ages rather quickly and loses its heat transfer capacity.

What would be your recomendations here. I'm not really good with hardware, but I have taken the TP apart before to make sure the fan hasn't accumulated dust, so I'm wondering what the danger is if I started to try and pull put the GPU.

Thanks for your help in advance.

Cheers,
-- stefan

[Shredder11]

I recently upgraded the CPU in my z61p 9452-3NG to a Core 2 Duo T7600 and that brought the CPU temp down by about 10 to 12°C, but alas the GPU is still overheating too easily and reaching 80°C+ under heavy load, e.g. 1080p videos or 720p with 50 or 60fps; other kinds of video take it to 74°C approx. This causes the video output to stutter and shake but the computer never shuts down, and I also have the TPFC app running. During the install of the CPU, I replaced the thermal paste with known good stuff and did this to the GPU as well. Other more senior and knowledgeable users on here, inform me that the heatsink assembly on mine is the best one to have; so I do not know how else to reduce the GPU temps as yet.

[RealBlackStuff]

Your machine has a T7400 CPU, no need to replace that.
The GPU is soldered onto the motherboard, and cannot be removed or replaced.
Your best bet is to remove the fan/cooler, clean off the old gunk from CPU, GPU and fan with Isopropyl alcohol, and then apply Arctic Silver 5 thermal paste.
The paste will take a few day before it settles in.
To check that both CPU and GPU make full contact with the fan, remove it again right after you first screwed down the fan.
The paste should show 'fully' on the fan bottom in nice rectangles the same size as the CPU and GPU.
If all looks well, put the fan back in (don't forget the small power cable).

[smomma]

Thanks a lot for the detailed answer.
In the meantime I have ordered Arctic Silver 5 Thermal Compound, and the two corresponding ArctiClean cleaning fluids.
I removed the heat sink according to the Hardware Maintenance Manual instructions without problems.
When I now look at the two places where I am supposed to apply the thermal paste, I see two different things:
The CPU has some residue of thermal paste on it which I will clean off with the cleaning fluid and then apply the Thermal Surface Purifyer (sounds like high-tech cosmetics like "Dramatically Different Moisturizing Lotion" ...).
On the GPU (which I identify by its ATI label printed on top), however, no such paste is present. Instead, on the opposite side (on the fan unit) there is a square of about twice the size of the GPU of some soft material, maybe 1.5 mm thick with an imprint of the GPU visible on it. (I guess I can post a photo of it if none of you has an idea what I am talking about ).
My question now: do I remove that square and replace it with thermal compund (a lot of it to account for the difference of height?), or do I apply the thermal compound on top of the square? Or do I have to go and buy "replacement goo" just for the GPU? (remember, it is the GPU that heats up most)
As always, I'm eternally grateful for your hints and tips.
-- stefan

[smomma]

... found the technical term for that "unidentified squishy thingy" between GPU und heatsink: they call it a "gap pad". Any recommendations on what to replace it with?

[RealBlackStuff]

I got mis-led by IBM/Lenovo's stupid name-giving, forgetting once again that the Z61 is a sister of the T60, NOT the T61 (where both nVidia GPU and CPU use thermal paste).
A thermal pad of about 0.8mm can be used as replacement.
Do NOT remove it and try to fill the gap with thermal paste!
And don't put thermal paste on that pad.

[Shredder11]

The z61p seems almost identical to the T60p, just that the latter does not have Firewire. There may be other more subtle differences but I am not aware of any.