[ltp] Thinkpad T43 cached read Speed(hdparm -T) mystery

[linux-thinkpad@linux-thinkpad.org]

Hi All:
	This is not strictly an thinkpad issue, but I'm running out of 
idea to check and people here are knowlegeable.
	I have a T43 with 1.86GHz, 553MHz FSB Pentium M Dothan(750)
processor and 2G of PC-4200 RAM. It also has a 60GB Hitachi 7200 rpm 
drive (HTS726060M9AT00)(PATA-to-SATA bridge, showing up as /dev/sda).  
When it was running a Ubuntu hoary a few months ago(too lazy to 
update), with vanilla 2.6.18 kernel, hdparm -T shows about 1800MB/sec.  
However, now I'm in hardy, with ubuntu 2.6.24-18 kernel, the hdparm -T 
show only less than 900MB/sec. The disk read speed hdparm -t shows the 
same result(about 37-38MB/sec).
	My questions are:
	0. If you have a T43(p) with comparable set up, what's your 
number?
	1. Does this mean my computer's bus speed is suddenly cut in 
half, as seen by linux? What's is the performance implication?
	2.What exactly does hdparm -T measure(processor bus speed?)?  
Is it a good gauge for performance? If it is not a good guage for 
performance, what is?
	3.What cause this dramatic reduction and performance penalty?  
Kernel? Fglrx?
	Thanks in advance for enlightenment!
								Jiang