[Exizl del Fuego]

Hi all,
I've a 500MHz G4 PowerMac with 896 MB of RAM running Mac OS X 10.4. It has its stock PCI video card, DVD-RAM drive and 40GB ATA drive, as well as a Firewire 400/800 PCI card. I've just installed a SIIG SATA 4-Channel PCI-M card with 4x500GB hard drives with the intent of striping them for use as a Retrospect dump for office backups, but I can't seem to get around a particular problem.

The drives are fully visible to Mac OS X, and Disk Utility reports no errors when setting them up as a RAID. However, when transferring data to any of the drives (single volumes or a full RAID volume), it'll scream through the first ~100MBs in the blink of an eye, hang for a moment, then continue its transfers in short bursts. Net effect is a transfer rate of approx. 1GB per hour. It's very slow and Retrospect usually gives up after about 50MBs.

I've tried different configurations of drives, some mounted, some not; striped or single; some powered down (in case I was taxing the power supply); different PCI slots for the SATA card -- all to no avail.

I finally decided I had a bum PCI card. I've got a replacement order with SIIG for the card, but today I brought in another of the same card I've been using at home flawlessly for about a year for my own server, and it's having the exact same problem.

I can't really think of where else the problem might reside. Has anyone come across anything like this? Any suggestions on what I might try next?

[DrBoar]

Do you use that mac as an off site backup to FTP to it?
If it is the backup computer have you tried using the disks individually? That is letting Retrospect treat them as "tapes".
I run two sets of backups, one to eternal external HD (treated as tapes) and a second set using FTP to a computer in an other room. The FTP is a bit slower as the the connetion from backup computer to hard disk is not a straight FireWire but 100Bits Ethernet-host-FireWire.

I have discovered that to keep the original FAT32 format on the FTP disk is a bad idea When the backupfile hits 4GB the partition becomes unreadable.

To bad that the OSX version is lagging so far behind the Win version. Especially the bug with all win files treated as new at every time the day light time sving goes on or off, irritates me.

[bowwowman]

Although I dont run it in a Raid/back up situation, I do have a SIIG/4ch SATA card running 4 drives of various sizes, notta problemo, in my current QS/867, and previously in my Sawtooth/DP450

Since the problem appears to be with the continuity/speed of the transfers AND with multiple cards, it may be related to exceeding the available bandwidth of the PCI bus &/or the motherboard controller chip that is in the process of dying.....for which there are not many solutions, unfortunately

HTH