Hard Drive Performance Issue

[ta2]

I have two RAID arrays currently setup on a ICH9R RAID controller:

2x160GB - RAID0 (1 partition)
4x750GB - RAID5 (1 partition)

I just started copying a 4.37GB file from the RAID0 to the RAID5. Everything is going fine, the transfer is about half-way completed after about 30 seconds, with another 30 seconds remaining. Then all of a sudden the estimated time remaining soars to 20 minutes. Neither hard drive is being significantly accessed otherwise.

Likewise, if I copy 30GB worth of files, the same process happens, every minute or so the transfer speed slows right down to about 50 times slower than normal.

Any ideas what is causing this?

Thanks.

[ta2]

The problem also occurs when I copy stuff from an external USB hard drive to the RAID 5 array. I ran HDTach on the drive and I get this very very strange graph:



I also burnt the Hitachi "Drive Fitness Test" bootable CD-ROM to disk and tested each of the four drives (quick test only, not full test), and it didn't show any problems.

[LegacyOne]

Odd do you get the same graph if you run HDTach again?

What OS & motherboard do you have?

Drivers and BIOS updated?

[alsenior]

i would try updating the bios and dirvers and try a different set of cables

[ta2]

I got the same graph when I ran HDTach the first time, except the flat bit at the time was shorter. I have an ASUS P5E and I am running Windows XP x64 Edition.