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IDE system bus speed

My dmesg produces the following:
ide: Assuming 33MHz system bus speed for PIO modes; override with idebus=xx

My drive is an ATA 100 disk but it's assuming only 33mhz. Can I just put the line idebus=100 in my lilo.conf - or does it go somewhere else?

Do you have a line that looks like those below anywhere? If so, what does it say UDMA(100) or something else? I am afraid the 33Mhz. might refer to your pci bus clock which probably is 33 mhz.

Code:

hde: 90069840 sectors (46115 MB) w/1916KiB Cache, CHS=65535/16/63, UDMA(100)

 /dev/ide/host2/bus0/target0/lun0: p1 p2 p3

hdh: max request size: 128KiB

hdh: 78165360 sectors (40020 MB) w/2048KiB Cache, CHS=65535/16/63, UDMA(100)

 /dev/ide/host2/bus1/target1/lun0: p1

jtshaw is right. If you're feeling adventurous, you might try 40 or 50 MHz. I'm pretty sure it's not 100 :)

Since you're probably using a UDMA mode for talking to the drive anyway, I doubt it makes any difference (though I'm far from being an expert on this subject).

When I wonder what the messages mean, I try grep -r for them in the kernel source. I noticed the same thing and have come to the conclusion it's nothing to worry about.

I think PIO was for very old hard drives before the ATA standard came along, so it wouldn't have any effect on a newer system. i have an old 100MHz pentium-s with ancient hard drive that boots with PIO messages.

Quote:

Originally posted by gnashley
I think PIO was for very old hard drives before the ATA standard came along, so it wouldn't have any effect on a newer system. i have an old 100MHz pentium-s with ancient hard drive that boots with PIO messages.

So it thinks my ATA100 drive is using PIO?

no, but if it WERE using PIO, that's the bus speed it would assume.

So the message is nothing to be concerned about.

Greetings. I have some "similar" problem. My dmesg after some cleaning up shows this:

Code:

ide: Assuming 33MHz system bus speed for PIO modes; override with idebus=xx

VP_IDE: IDE controller at PCI slot 00:07.1

VP_IDE: chipset revision 6

VP_IDE: not 100% native mode: will probe irqs later

VP_IDE: VIA vt82c686b (rev 40) IDE UDMA100 controller on pci00:07.1

    ide0: BM-DMA at 0x9000-0x9007, BIOS settings: hda:pio, hdb:DMA

    ide1: BM-DMA at 0x9008-0x900f, BIOS settings: hdc:pio, hdd:DMA

HPT370A: IDE controller at PCI slot 00:0e.0

PCI: Found IRQ 11 for device 00:0e.0

PCI: Sharing IRQ 11 with 00:09.0

HPT370A: chipset revision 4

HPT370A: not 100% native mode: will probe irqs later

HPT37X: using 33MHz PCI clock

    ide2: BM-DMA at 0xc400-0xc407, BIOS settings: hde:DMA, hdf:DMA

    ide3: BM-DMA at 0xc408-0xc40f, BIOS settings: hdg:pio, hdh:pio

hdb: CD-W540E, ATAPI CD/DVD-ROM drive

hdd: HL-DT-STDVD-ROM GDR8161B, ATAPI CD/DVD-ROM drive

hde: WDC WD800BB-00BSA0, ATA DISK drive

hdf: WDC WD200EB-00BHF0, ATA DISK drive

ide0 at 0x1f0-0x1f7,0x3f6 on irq 14

ide1 at 0x170-0x177,0x376 on irq 15

ide2 at 0xb400-0xb407,0xb802 on irq 11

hde: attached ide-disk driver.

hde: host protected area => 1

hde: 156301488 sectors (80026 MB) w/2048KiB Cache, CHS=155061/16/63

hdf: attached ide-disk driver.

spurious 8259A interrupt: IRQ7.

hdf: host protected area => 1

hdf: 39102336 sectors (20020 MB) w/2048KiB Cache, CHS=38792/16/63

ide-cd: passing drive hdb to ide-scsi emulation.

ide-cd: passing drive hdd to ide-scsi emulation.

hdb: attached ide-scsi driver.

hdd: attached ide-scsi driver.

Now, I'm worried about not 100% native mode that my controllers work in, and the fact that I do not have UDMA(100) shown after the disk information, like jtshaw posted. ide2 shows hde and hdf have DMA enabled, but is it really effective or not?

Should I add hde=scsi and hdf=scsi to the append instruction in lilo.conf? What would it change?

Oh, yes, I use Debian Sarge, actually Knoppix installed to hard disk.

Thanks,

Viktor