ML350 G5 slow write performance SATA E200i

[Jan Skrivervik]

I have a strange problem on a ML350 G5 dual core with 4x 250 GB SATA disks configured in RAID1 and W2K3 SBS. When copying one file (700 MB) from an XP client to the server RAID system the performance is the same as using an external USB HD. When copying 3 files (3x 700 MB) the performance is 1min 16s on the USB drive but 2min 24s for the RAID system ! The copy goes fast until 99% and then waits for a minute to complete. Same thing happens from Mac clients when copying large files (SMB or FTP). Latest and greates BIOS, firmware and drivers installed. Many thanks in advance for any help...