Slow disk transfers

Hello, I have a problem with my home server : the hard disk transfer rate started to be very slow since the day I've switched from RedHat 9 to CentOS 4.
The hardware have not be modified :
- Athlon XP 2000 - 512MB
- KT4 MSI Motherboard
- Hard disk is Western Digital WB1200JB

I've tried many settings with hdparm but I've never been higher than this rate :
Timing cached reads: 1068 MB in 2.01 seconds = 531.95 MB/sec
Timing buffered disk reads: 10 MB in 3.13 seconds = 3.19 MB/sec

Not only the disk is slow but also the CPU load under disk access seem to be quite high.

Somebody can help me ?

Thank you

****************************************************************
hdparm /dev/hda
/dev/hda:
multcount = 16 (on)
IO_support = 1 (32-bit)
unmaskirq = 1 (on)
using_dma = 1 (on)
keepsettings = 0 (off)
readonly = 0 (off)
readahead = 256 (on)
geometry = 65535/16/63, sectors = 120034123776, start = 0

****************************************************************
hdparm -I /dev/hda

/dev/hda:

ATA device, with non-removable media
Model Number: WDC WD1200JB-00CRA1
Serial Number: WD-WMA8C1920628
Firmware Revision: 17.07W17
Standards:
Supported: 5 4 3 2
Likely used: 6
Configuration:
Logical max current
cylinders 16383 4047
heads 16 16
sectors/track 63 255
--
CHS current addressable sectors: 16511760
LBA user addressable sectors: 234441648
device size with M = 1024*1024: 114473 MBytes
device size with M = 1000*1000: 120034 MBytes (120 GB)
Capabilities:
LBA, IORDY(can be disabled)
bytes avail on r/w long: 40 Queue depth: 1
Standby timer values: spec'd by Standard, with device specific minimum
R/W multiple sector transfer: Max = 16 Current = 16
Recommended acoustic management value: 128, current value: 128
DMA: mdma0 mdma1 mdma2 udma0 udma1 *udma2 udma3 udma4 udma5
Cycle time: min=120ns recommended=120ns
PIO: pio0 pio1 pio2 pio3 pio4
Cycle time: no flow control=120ns IORDY flow control=120ns
Commands/features:
Enabled Supported:
* READ BUFFER cmd
* WRITE BUFFER cmd
* Host Protected Area feature set
* Look-ahead
* Write cache
* Power Management feature set
Security Mode feature set
* SMART feature set
* Device Configuration Overlay feature set
* Automatic Acoustic Management feature set
SET MAX security extension
* DOWNLOAD MICROCODE cmd
* SMART self-test
* SMART error logging
Security:
supported
not enabled
not locked
not frozen
not expired: security count
not supported: enhanced erase
HW reset results:
CBLID- above Vih
Device num = 0 determined by the jumper
Checksum: correct

****************************************************************

smartctl -a /dev/hda
smartctl version 5.33 [i686-redhat-linux-gnu] Copyright (C) 2002-4 Bruce Allen
Home page is http://smartmontools.sourceforge.net/

=== START OF INFORMATION SECTION ===
Device Model: WDC WD1200JB-00CRA1
Serial Number: WD-WMA8C1920628
Firmware Version: 17.07W17
User Capacity: 120,034,123,776 bytes
Device is: In smartctl database [for details use: -P show]
ATA Version is: 5
ATA Standard is: Exact ATA specification draft version not indicated
Local Time is: Wed Sep 13 15:02:00 2006 CEST
SMART support is: Available - device has SMART capability.
SMART support is: Enabled

=== START OF READ SMART DATA SECTION ===
SMART overall-health self-assessment test result: PASSED

General SMART Values:
Offline data collection status: (0x82) Offline data collection activity
was completed without error.
Auto Offline Data Collection: Enabled.
Self-test execution status: ( 0) The previous self-test routine completed
without error or no self-test has ever
been run.
Total time to complete Offline
data collection: (4680) seconds.
Offline data collection
capabilities: (0x3b) SMART execute Offline immediate.
Auto Offline data collection on/off support.
Suspend Offline collection upon new
command.
Offline surface scan supported.
Self-test supported.
Conveyance Self-test supported.
No Selective Self-test supported.
SMART capabilities: (0x0003) Saves SMART data before entering
power-saving mode.
Supports SMART auto save timer.
Error logging capability: (0x01) Error logging supported.
No General Purpose Logging support.
Short self-test routine
recommended polling time: ( 2) minutes.
Extended self-test routine
recommended polling time: ( 87) minutes.
Conveyance self-test routine
recommended polling time: ( 5) minutes.

SMART Attributes Data Structure revision number: 16
Vendor Specific SMART Attributes with Thresholds:
ID# ATTRIBUTE_NAME FLAG VALUE WORST THRESH TYPE UPDATED WHEN_FAILED RAW_VALUE
1 Raw_Read_Error_Rate 0x000b 200 200 051 Pre-fail Always - 0
3 Spin_Up_Time 0x0007 100 095 021 Pre-fail Always - 5750
4 Start_Stop_Count 0x0032 100 100 040 Old_age Always - 700
5 Reallocated_Sector_Ct 0x0033 199 199 140 Pre-fail Always - 5
7 Seek_Error_Rate 0x000b 200 200 051 Pre-fail Always - 0
9 Power_On_Hours 0x0032 067 067 000 Old_age Always - 24248
10 Spin_Retry_Count 0x0013 100 100 051 Pre-fail Always - 0
11 Calibration_Retry_Count 0x0013 100 100 051 Pre-fail Always - 0
12 Power_Cycle_Count 0x0032 100 100 000 Old_age Always - 637
196 Reallocated_Event_Count 0x0032 198 198 000 Old_age Always - 2
197 Current_Pending_Sector 0x0012 200 200 000 Old_age Always - 0
198 Offline_Uncorrectable 0x0012 200 200 000 Old_age Always - 0
199 UDMA_CRC_Error_Count 0x000a 200 200 000 Old_age Always - 0
200 Multi_Zone_Error_Rate 0x0009 200 200 051 Pre-fail Offline - 0

SMART Error Log Version: 1
No Errors Logged

SMART Self-test log structure revision number 1
No self-tests have been logged. [To run self-tests, use: smartctl -t]


Device does not support Selective Self Tests/Logging
.

Relevant Pages