AMAROK and software RAID

I have problem play music with Amarok on my openSUSE 11 running an software RAID5 file system.
Must confess that I find it strange that it is possible to run a HD movie in Mplayer with no distortion and even listen to my MP3 music whit jampal whit no problem.

Copying any mp3 file from one place to another happens within seconds.

But Playing a mp3 music file in Amarok is distorted. It sounds as if the data is not read as fast as needed. This is the case if the mp3 music exists on a raid5 partition but not if the file is put in a partition that is not a part of the raid array.

Configuration:

Kernel: Linux 2.6.25.18-0.2-pae i686
GUI: 4.0.4 (KDE 4.0.4 >= 20080505) “release 33.3”
AMAROK: 1.4.10-100.pm.1-i586 from http://packman.iu.bremen.de/suse/11.0

CPU
Intel(R) Pentium(R) 4 CPU 3.00GHz
3 GB in memory

Graffa
GeForce 7600 GS

4 SATA hard drivers
/dev/sda: Maxtor 6B300S0: 300 GB
/dev/sdb: WDC WD7501AALS-00J7B0: 750 GB
/dev/sdc: WDC WD7500AAKS-00RBA0: 750 GB
/dev/sdd: ST3750330AS: 750 GB

sda: is holding one windows system and one openSUSE10.3 system and all systems swap file.

sdb, sdc and sdd is all partitioned in 4 primary partitions
sdx1: 98GB
sdx2: 1GB
sdx3 500GB
sdx4: 98 GB

sdb4, sdc4 and sdd4 is building the md0 raid5 system holding the primary openSUSE11 system
sdb2 is holding the boot partition.

sdb3, sdc3 and sdd3 is building md1 holding all data ( and my music)

sdc2 and sdd2 is not used but will hold the boot partition of the new openSUSE11.1 system when it will be installed on md3

sdb1, sdc1 and sdd1 is partitioned in the same size but have not yet formed the md3 raid.
Sdc1 is holding a “stable” openSUSE11 system for security reasons.

Putting 4 GB music on the sdc1 drive and testing playing some MP3’s from that single partition system or from the system running on md0 is not distorted. But music stored on md0 or as planned stored om md1 will bi distorted as I play it. This regardless if I uses the Yauap or the Xine sound system are used.

Could some one advise?

Bizarre. The only thing I can think of is that your disk interrupts are somehow conflicting with the sound card interrupts. Can you post the output of:

cat /proc/interrupts

Does your sound card have a separate IRQ line?

CPU0 CPU1
0: 131 0 IO-APIC-edge timer
1: 2 0 IO-APIC-edge i8042
4: 6 0 IO-APIC-edge
6: 5 0 IO-APIC-edge floppy
7: 0 0 IO-APIC-edge parport0
8: 0 0 IO-APIC-edge rtc0
9: 0 0 IO-APIC-fasteoi acpi
12: 4 0 IO-APIC-edge i8042
14: 44949 0 IO-APIC-edge ata_piix
15: 0 0 IO-APIC-edge ata_piix
16: 313331 0 IO-APIC-fasteoi uhci_hcd:usb4, HDA Intel, nvidia
18: 0 0 IO-APIC-fasteoi uhci_hcd:usb3
19: 166983 0 IO-APIC-fasteoi ata_piix, uhci_hcd:usb2
20: 10010 0 IO-APIC-fasteoi eth0
23: 2 0 IO-APIC-fasteoi uhci_hcd:usb1, ehci_hcd:usb5
NMI: 0 0 Non-maskable interrupts
LOC: 864369 602301 Local timer interrupts
RES: 188129 148802 Rescheduling interrupts
CAL: 549269 726405 function call interrupts
TLB: 11894 16292 TLB shootdowns
TRM: 0 0 Thermal event interrupts
SPU: 0 0 Spurious interrupts
ERR: 0
MIS: 0

The sound card is an on board devise. The IRQ is 16 and active.
" 16: 332457 0 IO-APIC-fasteoi uhci_hcd:usb4, HDA Intel, nvidia" from the interupts file. Any clue?