Very Computer

I have:
Athlon 650 on a ASUS K7M motherboard.
8GB HD on primary controller (hda)
8GB HD on secondary controller [master] (hdc)
CD-ROM on secondary controller [slave] (hdd)

I have DMA enabled via hdparm -d1 on both hda and hdc. Without this I
lose over half of my speed. However, hdc is very slow compared to hda.
Running hdparm -Tt /dev/hda /dev/hdc gives me

/dev/hda:
 Timing buffer-cache reads:   128 MB in  2.41 seconds = 53.11 MB/sec
 Timing buffered disk reads:  64 MB in  5.83 seconds = 10.98 MB/sec

/dev/hdc:
 Timing buffer-cache reads:   128 MB in  2.41 seconds = 53.11 MB/sec
 Timing buffered disk reads:  64 MB in 31.67 seconds =  2.02 MB/sec

Is there some fundamental reason why hdc is less than 20% of the speed
of hda? Am I incorrect in assuming that both controllers should have the
same throughput?

--
In times of crisis, it is of utmost importance to keep one's head.
- M. Antoinette

Putting a CDROM on the same interface as a hard drive will slow down
things, but what you're reporting here seems a bit slow even for that
problem - at least compared to a setup I used to have. check to see if
there are any differences on the setups of the two harddrives with hdparm -
i

Quote:>I have:
>Athlon 650 on a ASUS K7M motherboard.
>8GB HD on primary controller (hda)
>8GB HD on secondary controller [master] (hdc)
>CD-ROM on secondary controller [slave] (hdd)

>I have DMA enabled via hdparm -d1 on both hda and hdc. Without this I
>lose over half of my speed. However, hdc is very slow compared to hda.
>Running hdparm -Tt /dev/hda /dev/hdc gives me
<snip>
>Is there some fundamental reason why hdc is less than 20% of the speed
>of hda? Am I incorrect in assuming that both controllers should have the
>same throughput?

Quote:> Putting a CDROM on the same interface as a hard drive will slow down
> things, but what you're reporting here seems a bit slow even for that
> problem - at least compared to a setup I used to have.

I get the same type of throughput (hda=11MB/s;hdb=2MB/s), so I assume
that it's the hard drive. I checked the BIOS settings thoroughly and
everything that I could think of from the bottom up.

hdb does not accept DMA. If I "hdparm -d1 /dev/hdb" I get some error
messages from the kernel about the drive timing out and it resets the
drive. I can no longer change the DMA setting on hda using hdparm. I had
to add "ide0=dma" to lilo.conf to enable DMA on hda.

hdparm -i does not show anything suspicious. The only real differences
are minor and expected. (i.e. the newer wierd drive shows newer pio
modes, etc.)

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