Originally posted by StylinGolfShoes
IBMS are better using more power
Do you have anything else to say that might back up your opinion? Opinions are fine, but should be backed up by factual evidence.
Anyways, to answer your question:
The T30 uses a Pentium4-M. P4-Ms use up a lot of energy, which translates into higher drain on the battery. Furthermore, in an effort to conserver battery life, P4-Ms use speedstep to lower the clock speed of the CPU, which would explain why it gets slower at times.
Your dad's Dell probably uses a more energy-efficient design. It may include a Pentium-M CPU which gives: a) More bang per clock cycle meaning lower clock speeds b) Better overall energy usage.