SCSI Performance on Dual Opteron 244 4G

18:03:21  up 116 days,  3:05,  1 user,  load average: 0.78, 1.05, 1.00
192 processes: 190 sleeping, 1 running, 1 zombie, 0 stopped
CPU states:  cpu    user    nice  system    irq  softirq  iowait    idle
          total    9.0%    0.0%    2.9%   0.0%     0.4%    8.4%   78.8%
          cpu00   10.1%    0.1%    3.3%   0.0%     0.1%   12.7%   73.2%
          cpu01    7.9%    0.0%    2.5%   0.0%     0.7%    4.1%   84.4%
Mem:  3538168k av, 3127276k used,  410892k free,       0k shrd,  219364k buff
                  1705180k actv,  851480k in_d,   40724k in_c
Swap: 2040244k av, 280k used, 2039964k free, 1454620k cached

root@r1 [~/trungson/shells]# hdparm -tT /dev/sda
/dev/sda:
Timing buffer-cache reads:   2532 MB in  2.00 seconds = 1266.00 MB/sec
Timing buffered disk reads:   50 MB in  3.12 seconds =  16.03 MB/sec

Might be some problem w/ the disk reads