bad performance on RAID 5

[Sevrin Robstad <quackyo@start.no>]

I'm suffering from bad performance on my RAID5.

a "echo check >/sys/block/md0/md/sync_action"

gives a speed at only about 5000K/sec , and HIGH load average :

# uptime
20:03:55 up 8 days, 19:55,  1 user,  load average: 11.70, 4.04, 1.52

kernel is 2.6.18.1.2257.fc5
mdadm is v2.5.5

the system consist of an athlon XP1,2GHz and two Sil3114 4port S-ATA PCI 
cards with a total of 6  250gb S-ATA drives connected.

[root@compaq ~]# mdadm --detail /dev/md0
/dev/md0:
        Version : 00.90.03
  Creation Time : Tue Dec  5 00:33:01 2006
     Raid Level : raid5
     Array Size : 1218931200 (1162.46 GiB 1248.19 GB)
    Device Size : 243786240 (232.49 GiB 249.64 GB)
   Raid Devices : 6
  Total Devices : 6
Preferred Minor : 0
    Persistence : Superblock is persistent

    Update Time : Wed Jan 17 23:14:39 2007
          State : clean
 Active Devices : 6
Working Devices : 6
 Failed Devices : 0
  Spare Devices : 0

         Layout : left-symmetric
     Chunk Size : 256K

           UUID : 27dce477:6f45d11b:77377d08:732fa0e6
         Events : 0.58

    Number   Major   Minor   RaidDevice State
       0       8        1        0      active sync   /dev/sda1
       1       8       17        1      active sync   /dev/sdb1
       2       8       33        2      active sync   /dev/sdc1
       3       8       49        3      active sync   /dev/sdd1
       4       8       65        4      active sync   /dev/sde1
       5       8       81        5      active sync   /dev/sdf1
[root@compaq ~]#


Sevrin