DoesT41 run much faster than X31?

[smartzhao]

IBM ThinkPad X31 NCH
PM1.6G/256M DDR333/40G(4200)/12.1XGA/ATI Radeon 16M /

IBM ThinkPad T41 7KH
PM1.6G/256M DDR333/40GB(5400)/14.1XGA/ATI 7500 32M/


what`s the performance gap between X31-nch with T41-7kh ?
if i change the hardisk of X31 from 80gn 4200rpm to 5k80 5400rpm?
i think X31 should have a better performance. and then what`s the gap between x31 and t41?
does X31 support ram with DDR333? i remember it only support ddr266.

the main use of my laptop is only for programming especially with java.
never paly any game, only a few dvd film for fun. so i need a better performance for programming, compiling,testing and running.

i will add the ram from 256m to 1024m.

T41 price is only expensive 100+$ than X31 in China. i will buy a laptop in this july and now i am irresolute to determine which one should i buy?