Vladimir's Tech Blog

Wrong tradeoffs and hardware design

March 28, 2008

Some people know how to build parts of a computer together, know what makes up a good computer and what computer users really need. Some others do not. It is a pity, that responsible engineers at a major computer manufacturer belong to the latter category.

Lets have a look at my two and a half year old Thinkpad T43.

Thinkpad T43

This notebook is based on a pretty modern Pentium M CPU with Dothan core, that features all the power saving techniques:

  • variable clock frequency
  • dynamically changing the voltage
  • turning off unneeded parts of the core (like cache) And in fact, the CPU consumes extremely little power - between 5W and 20W, under both Windows and Linux 2.6.

Little power consumption means little heat, the notebook should run on battery for a long time and be quiet. But it is much more noisy than my desktop computer in fact.

Lets have a closer look at the design (I mean, not how cute it is from the outside, but what are the intrinsic values):

  • the north bridge (1) has no heat sink at all!
  • the south bridge (2) has no heat sink and buried under the wireles LAN card (3)
  • they have enough space for a archaic parallel port (4) but not for connecting the north bridge (working at a high frequency BTW - FSB 800) to the heat pipe!? The patented trackpoint is above.
  • after couple of minutes the fan (5) goes up but it does not run on a same speed - it changes the speed (and the noise frequency) every 2 seconds and drives you crazy
  • the cage for the PCMCIA (6) has lot of holes, so instead of the proper air flow through all the important components the fan sucks the cold air directly through the holes in the cage (6) from the outside. But, as you see, the fan is not the only component that completely sucks here.
  • I do not use the infrared port, but if I wished, I can not imagine it would work with the big ( 1 centimeter ) dense chunk of the dust (shown in magenta on the picture) between the infrared LED (marked red on the picture) and the case
  • even the power supply that BTW you need every 1.5-2 hours and that has no movable parts makes noises. Do they build in small speakers to plague their customers?

Infrared LED


  • vacuum-cleaning alone extended the starting peace and quiet period from 10 to about 40 minutes
  • I even considered covering the north bridge with a copper plate using heat conducting adhesive and connecting it to the existing heat pipe
  • the fan is very special and there is no space left around it, so you can not replace it with a bigger one

It is unbelievable, how compact the semiconductor parts were even 2.5 year ago. So if you do not waste the space and throw away all the unneeded crap like modem, parallel ports, dvd-drive, you can easily create something as lean as a MacBook Air.

So if you do not know how to design computers, do not do it, do something else! Oops, they already desided to give up.

And on next opportunity I will review the enterprise software development tools from the same vendor.


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