Quoting Matthew Emmerton <[EMAIL PROTECTED]>: > [ cc'ing Soren since he's the ATA guru ] > > > Dec 30 23:27:00 ecserv13 /kernel: ad0: trying fallback to PIO mode > > Dec 30 23:27:00 ecserv13 /kernel: ata0: resetting devices .. done > > > > The test continues to run with the ata controller in PIO mode, with > > slower performance, and higher load average. > > > > Once the master drops to PIO, attempts to access the slave then cause > > it to drop to PIO. > > Are you using 80-conductor cables on all your drives? These are required to > get consistent high throughput, and running without them may cause the > problems you're seeing.
Thanks for the information about the design of IDE etc, and the suggestion about the cables. I was about to shuffle things to get the disks onto separate channels, but I now see that would be a mistake as my CD drive would share a cable with a disk. Anyway, they all have the 80 conductor cable. I forgot to add some environmental and other information. The 4 AMD systems are in Aopen hx08 towers, with 400 watt power supplies, and 5 auxilliary fans (in addition to the power supply fan, and fan on each cpu). They are in an air conditioned machine room. The CPU and motherboard temperatures are within spec. I mention this as I note many reported AMD system problems traced to overheating. All drives are installed in removeable drive bays. I don't have the make/model on hand right now. They were $19 CAD. ($13USD). The low cost makes me suspicious now, but... I'm running the same tests on 4 single processor 2.4GHz Intel systems. They have not failed in this manner so far. Initially, I had 1GB memory modules in the AMD systems (I can't remember the make) and the systems froze and rebooted randomly. I moved to Crucial 512MB modules to cure that problem. ---------------------------------------- This mail sent through www.mywaterloo.ca To Unsubscribe: send mail to [EMAIL PROTECTED] with "unsubscribe freebsd-questions" in the body of the message