Hi,

I've just noticed something strange today. After removing my 4 drive
RAIDframe set (interactive performance under disk load is not good), I put
in two large IDE disks, each on its own channel on a PCI card (PCI0648)
and two SCSI disks.

When copying between the two IDE disks, I saw network transfers drop from
around 1.2 megs a second (between my machine and ftp.netbsd.org) to less
than 20k a sec! I stopped and restarted the copy several times, tried
nicing it, but it's definitely happening. When copying between SCSI and
IDE, the speed only drops to around 700k - 800k sec. SCSI to SCSI shows no
network slowdown (as expected).

I know that IDE has more overhead than SCSI, but this is crazy! Does
anyone else run multiple IDE devices without problems? If so, please tell
me what kind of IDE card you're using and how you've tested it.

More information:
The system is a PM 9600, 400 MHz 604ev, lots of memory, running 1.6.2.
IDE:
pciide0 at pci1 dev 13 function 0: CMD Technology PCI0648 (rev. 0x01)
pciide0: bus-master DMA support present
pciide0: primary channel configured to native-PCI mode
pciide0: using irq 27 for native-PCI interrupt
SCSI:
esiop0 at pci0 dev 13 function 0: Symbios Logic 53c896 (ultra2-wide scsi)
esiop0: using on-board RAM
esiop0: interrupting at irq 23
scsibus0 at esiop0: 16 targets, 8 luns per target
esiop1 at pci0 dev 13 function 1: Symbios Logic 53c896 (ultra2-wide scsi)
esiop1: using on-board RAM
esiop1: interrupting at irq 23
Both IDE drives are running at Ultra-66 speed:
wd0 at pciide0 channel 0 drive 0: <Maxtor 6Y120P0>
wd0: drive supports 16-sector PIO transfers, LBA addressing
wd0: 114 GB, 238216 cyl, 16 head, 63 sec, 512 bytes/sect x 240121728 sectors
wd0: drive supports PIO mode 4, DMA mode 2, Ultra-DMA mode 6 (Ultra/133)
wd0(pciide0:0:0): using PIO mode 4, Ultra-DMA mode 4 (Ultra/66) (using DMA data transfers)
pciide0: secondary channel configured to native-PCI mode
wd1 at pciide0 channel 1 drive 0: <Maxtor 7Y250P0>
wd1: drive supports 16-sector PIO transfers, LBA48 addressing
wd1: 233 GB, 486344 cyl, 16 head, 63 sec, 512 bytes/sect x 490234752 sectors
wd1: drive supports PIO mode 4, DMA mode 2, Ultra-DMA mode 6 (Ultra/133)
wd1(pciide0:1:0): using PIO mode 4, Ultra-DMA mode 4 (Ultra/66) (using DMA data transfers)

Thanks,
John Klos