IDE numbers

Bruce M Beach (brucemartinbeach@21cn.com)
Thu, 8 Aug 2002 12:19:22 +0000 (UTC)


Hello All

I'm just sending these numbers because they are interesting. I bought
a couple of SCSI drives(seagate) a while ago so I thought I would try
a simple performance test. I copied a 9.2Gb file (using G=1024^3) and
timed it in the following manner:

1) Partition to Partition(IDE) hda1 to hda3 # wd drive
2) Partition to SCSI drive hda2 to sda1 # wd to seagate
3) SCSI drive to SCSI drive sda1 to sdb1 # seagate to seagate

and got the following numbers

time cp TEMP.tar ... hda3->hda1 49m18.320s ~ 3,339,200.9 bytes/s
time cp TEMP.tar ... hdc1->sda1 51m16.493s
time cp TEMP.tar ... sda1->scb1 5m41.388s ~ 28,936,063 bytes/s

At first I thought the IDE numbers were a little bit slow but thought
the transfer must read and write the 9.2Gb so maybe I should double
the rate and after all the 33 Mhz is just the IDE bus rate. I was suprised
at the IDE -> SCSI transfer time except the the SCSI transport(adaptec) is
on another PCI bus and maybe there is significant latency across the
bridge. The real surprise was the SCSI -> SCSI and the ultimate result
of this little experiment was that I bought 2 more SCSI drives.

I looked around a little bit to see if dmesg had anything to say
and found the following lines:

...
Real Time Clock Driver v1.10e
Non-volatile memory driver v1.1
block: 128 slots per queue, batch=32
Uniform Multi-Platform E-IDE driver Revision: 6.31
ide: Assuming 33MHz system bus speed for PIO modes; override with idebus=xx
PCI_IDE: unknown IDE controller on PCI bus 00 device f9, VID=8086, DID=248b
PCI: Device 00:1f.1 not available because of resource collisions
PCI_IDE: chipset revision 2
PCI_IDE: not 100% native mode: will probe irqs later
ide0: BM-DMA at 0xffa0-0xffa7, BIOS settings: hda:DMA, hdb:DMA
ide1: BM-DMA at 0xffa8-0xffaf, BIOS settings: hdc:pio, hdd:pio
hda: ST360021A, ATA DISK drive
hdb: 16X10, ATAPI CD/DVD-ROM drive
ide0 at 0x1f0-0x1f7,0x3f6 on irq 14
hda: 117231408 sectors (60022 MB) w/2048KiB Cache, CHS=7297/255/63
Partition check:
/dev/ide/host0/bus0/target0/lun0: p1 p2 p3
...

What 'PCI: Device 00:1f.1' is I couldn't determine except for a binary
in /proc/bus/pci/00/1f.1. The PCI slots share resources across
several bus's, (i.e. Slots 1 & 2 share with the SCSI trasport)
and the only anomaly is that due to the onboard video having only 4Mb
ram and there being no AGP slot, there is a PCI video card
on bus 3.
Please cc any comments to me.

Bruce
`

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