Re: ATA-100 disk under 2.2.18 -- horrible performance
On 07 Jan 2001 03:58:45 -0500, Arcady Genkin said:
> I have an IBM ATA-100 30G harddrive, attached to a ASUS CUSL2-C (Intel
> 815EP-based) mobo.
>
> The kernel is not even using the drive in UDMA mode. The performance
> is *horrible*: every time I copy to the disk the CPU usage goes up all
> the way and I'm seeing things like "load average: 5.47, 5.02, 3.27",
> which is only caused by disk access.
>
> ,----[ dmesg ]
> | PCI_IDE: unknown IDE controller on PCI bus 00 device f9, VID=8086, DID=244b
> | PCI_IDE: not 100% native mode: will probe irqs later
> | ide0: BM-DMA at 0xa800-0xa807, BIOS settings: hda:DMA, hdb:pio
> | ide1: BM-DMA at 0xa808-0xa80f, BIOS settings: hdc:DMA, hdd:pio
> | hda: QUANTUM FIREBALLP LM10.2, ATA DISK drive
> | hdc: IBM-DTLA-307030, ATA DISK drive
> | ide0 at 0x1f0-0x1f7,0x3f6 on irq 14
> | ide1 at 0x170-0x177,0x376 on irq 15
> | hda: QUANTUM FIREBALLP LM10.2, 9797MB w/1900kB Cache, CHS=19906/16/63, UDMA
> | hdc: IBM-DTLA-307030, 29314MB w/1916kB Cache, CHS=59560/16/63
> `----
> As you can see, the other HD (which is an ATA-66 Quantum) is at least
> used in UDMA mode.
>
> What is the reason the kernel dislikes the drive so much? ;^)
> Do you suppose I've missed some option in kernel configuration? Any
> other possible reasons? Could the fact that the whole drive is one
> 30G ext2fs partition have anything to do with the slowness?
>
Well i am using the identical ibm drive on an abit mb without
ATA100 support. In my kernel config i set IDEDMA_AUTO=y so the
kernel automatically enables DMA.
When i run hdparm -i it shows:
UDMA modes: mode0 mode1 mode2 mode3 *mode4 mode5
And hdparm -t shows disk reads about 30MB/sec.
Maybe you have to manually enable DMA for this drive.
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