[LIH]hdparm, old hdds and new system

[L.V.Gandhi <lvg...@ma...>]

I had PIII 866 mhz pc with 256 mb sdram 815 mb.
Now I have changed over the  system to Athlon XP 2400+ on ASUS A7N8X deluxe MB 
with 256 MB(333 mhz) DDR ram.
Hdds are same. One 20 GB seagate 5400 rpm as hda and other 40GB Samsung 7200 
rpm as hdb.
Previous results of hdparm -tT /dev/hdx are as follows
[root@lvghomepc lvgandhi]# hdparm -tT /dev/hda

/dev/hda:
 Timing buffer-cache reads:   128 MB in  1.31 seconds = 97.71 MB/sec
 Timing buffered disk reads:  64 MB in  2.16 seconds = 29.63 MB/sec
[root@lvghomepc lvgandhi]# hdparm -tT /dev/hdb

/dev/hdb:
 Timing buffer-cache reads:   128 MB in  1.43 seconds = 89.51 MB/sec
 Timing buffered disk reads:  64 MB in  1.65 seconds = 38.79 MB/sec
 
Now it is  as follows.
[root@lvghomepc lvgandhi]# hdparm -tT /dev/hda

/dev/hda:
 Timing buffer-cache reads:   128 MB in  0.37 seconds =345.95 MB/sec
 Timing buffered disk reads:  64 MB in  4.10 seconds = 15.61 MB/sec
[root@lvghomepc lvgandhi]# hdparm -tT /dev/hdb

/dev/hdb:
 Timing buffer-cache reads:   128 MB in  0.38 seconds =336.84 MB/sec
 Timing buffered disk reads:  64 MB in  2.19 seconds = 29.22 MB/sec

While the first has increased, second has decreased. Any explanation will be 
appreciated. Further what is the significance of both values in real usage.
-- 
L.V.Gandhi
203, Soundaryalahari Apartments, Lawsons Bay colony, Visakhapatnam, 530017
MECON, 5th Floor, RTC Complex, Visakhapatnam AP 530020 INDIA