General Notes of T43 Power Consumption and Cooling System

[x3lda]

I bought a T43 and it has it's ups and it has downs. One major downer has been the power consumption and cooling.

Where as most dells inspiron 6000 consume 11 watts at idle, the t43 takes 14. On a 6 cell battery, that's 30% more power consumption while having the same usage and same screen brightness. Also, dells are cooler and heat is distributed more evenly unlike the hot southbridge and gpu of thinkpads.

On my thinkpad the entire cooling system is composed of one sheet of copper, some welted fins, copper spacer attachments, and three copper tubes that seem like heatpipes.



Two of the heatpipes are for the CPU and one longer one is for the GPU. The northbridge die is exposed with no heatsinks. The southbridge rests below the wireless card and is also bare with no heatsink. I have no yet lifted out the 56K daughter board to check if the power mosfets which are probably also bare.


Notes of the Cooling System

If you take off the cooling array/heatsink, you notice that the CPU has a gray compound on it which I cannot identify. Some others have a white compound. If you run Prime95, you notice that the heatpipes gets hot and conducts adequately along the length of the heatpipe. This is very good for a laptop so thin.

The GPU has one heatpipe above the copper plate. If you run a 3D graphics demo to heat up the GPU, the GPU gets extremely hot but the heatpipe is only warm at near the fan. This indicates that it is not conducting very well. Beneath the heatsink, there is a thermal compound and then a thermal pad and then the GPU casing and the the GPU die. This is a very inefficent setup to begin with along with the ineffective heatpipe. When I run 3D Mark and then check TP4xfancontrol, the GPU is by far the hottest thing at 66 while the CPU maxes out at 57-58.

Now to the fan. The fan is attached to the cooling system and looking at the blades, it tries to be a blower style fan since the blades are at a right angle to the axis of spin. The thing with that is, blowers work by taking air from the top and bottom of the fan and spitting it out the side. However, the t43 base is immediately below the fan and the keyboard rests directly above it. Therefore, no air gets on either top or bottom of the blower. If you take a look at dells, there are air inlets on the bottom and air comes out the back. Instead, thinkpad's cool by just having the fan suck in air the same place as it goes out. This is not only inefficient, it wastes power since air currents are at conflict.

As for the fins, they are short and they are welted. Iwould have expected IBM to use skived fin process. Welting is fast and cheap but conduction significantly lower. The stacking of copper is also odd instead of making it from a solid block.

A shortcoming of many notebooks is that they don't provide diode temperatures and simply provide the socket temperatures.

That's about it, I'll add more if I think of more.[/img]

[agarza]

I've a T42p and the same happens to me.
The thing gets too hot.

Here some tips:

1. Did you take a look at this thread:
http://forum.thinkpads.com/viewtopic.php?t=24621
(It talks about applying Arctic Silver 5, a thermal compound based on 99.9% of pure silver, which helps dissipating the heat more effectively.
2. If you decide to change the stock thermal grease be careful and follow the link above.
I did the same procedure as nirvana001, removing the thermal pad and the brown goop on the heatsink area that contacts the GPU. It's difficult, you should get the 2-bottle ArctiClean.

My CPU now runs @ 50-53C when downloading files, listening to music & browsing the net. My GPU runs about 2-3 degrees hotter than the CPU.

The temps may seem higher, but when the gaming time starts, after playing some time in game, I switch back to the T43 Fan Control I see the CPU has only reach about 62-64C (sometimes maybe more) and the GPU about 75C which drops very fast when I switch from the game to Windows.

The Arctic Silver 5 compound has yet to get its consistency needed for 100% heat dissipation (as it needs more than 200 hours to settle and fill the microscopic gaps on the CPU/GPU/Heatsink.

/////

In addition to your opinion about the efficiency of the cooling architecture, yes, it sucks. The northbridge/southbridge should have been also linked with another heatsink or at least the northbridge (above the GPU) to help dissipate heat.

Another factor that lead to CPU/GPU increase is the Wi-Fi card being used to download stuff, while underneath it there's the souuthbridge die also generating more heat

You should wait about 20/25 days to see the real results Arctic Silver 5 has to offer. But I did noticed that the laptop didn't get very hott when gaming.

Right now I'm complaining of the keyboard flexing. Palm rest, right side, below the right Alt & Ctrl keys. I press the palmrest and I feel the thing flexing, as a result the keys on the low right side are a bit loose and when typing them they make a horrible sound.
Any way to fix this?

[x3lda]

1) I use Artic Silver Ceramique because AS5 takes time and Ceramique works just as well and I have a 22gram thingy and it's not electrically conductive. However, IMO, it is useless because it only helps transfer the heat to the heatsink but in our case, the heatsink sucks and can't get the heat to the fin's well so there really isn't a point. I removed the stock paste with pure isopropyl and then applied the ceramique without significant difference. Before it was 42C now it's 41C at idle and the max temps are about the same (2-4 degree difference tops) around 55-60 since it's cooler now in PA.

2) 50-53C measure from the die? or what the tp4xfancontrol reports to you? Because it appears that all the temperature are not diode temps but rather socket temperatures. You can tell because if you run prime95, it takes a while for the temperature to change. If it was diode temps, the temperature would skyrocket within 20 seconds and drop really fast too which does not happen in my case.

3) as for the wifi, i think it's insignificant if access connections is correct. 12.6mW is nothing, plastic can dissipate that heat. It's more like to be the south bridge with all the IO traffic that's causing the heat.

[agarza]

Can you post your CPU/GPU temps idle (not Wifi enabled) and Max LOAD.

I think also that some Thinkpads may vary to other Thinkpads in the way of the heat build up. Some users have reported that their laptops run cooler, while others complain about the heat issues.

When I got my T42p the temps were about 48-50C surfing web and downloading big files. The GPU about 52C. Almost the same temperatures I'm getting using AS5. I don't know how much degrees off AS5 could achieve when maximum performance on the compound is achieved.

I've noticed that in NHC, when I set my CPU voltage to the 0.7xx values, the CPU is still running hot (45-47C) I've never achieved a stable temperature of 39C as nirvana001's post stated.

Maybe some versions of the Dothan/Sonoma processors run at very different setups and some of them gets very hot, while others not.

It would be coold to have a custom-made heatsink that covered the north/south bridges applying AS5 on them and see the results.

------------

another thing:
does the left side of your T43 keyboard gets TOO hot??
Mine not too much, when gaming it becomes more hot, but no the way it was with the stock compound.