Re: scsi & ide disk speeds?

[Mike Dresser <mdresser_l@windsormachine.com>]

> I've always thought SCSI disks are faster than the IDE disks, but this
> does not seem to be the case (at least for device reads). Anyone have
> a good explanation, or am I missing something?

Well, you've got ancient SCSI hard drives, I'm not surprised.  Those
drives are simply not all that fast in the first place.

> BTW: Is there a good place to put in the hdparm -d 1 /dev/hda
> somewhere at the boot scripts? I've added it to the
> /etc/init.d/bootmisc.sh script. It would be very nice to have this as
> default without making any manual changes, but I assume there are
> reasons why not.

That's fine, I put my own hdparm file in /etc/init.d

> Box1:
> Sep  8 20:49:08 box1 kernel:   Vendor: IBM       Model: DDRS-39130D       Rev: DC1B
> Sep  8 20:49:08 box1 kernel:   Type:   Direct-Access                      ANSI SCSI revision: 02
> Sep  8 20:49:08 box1 kernel: (scsi0:A:6): 40.000MB/s transfers (20.000MHz, offset 8, 16bit)
>
> Box2:
> Sep 10 10:51:01 box2 kernel:   Vendor: IBM       Model: DNES-309170W      Rev: SA30
> Sep 10 10:51:01 box2 kernel:   Type:   Direct-Access                      ANSI SCSI revision: 03
> Sep 10 10:51:01 box2 kernel: (scsi0:A:6): 11.626MB/s transfers (5.813MHz, offset 8, 16bit)

See the 11.626 MB/s line on box2?  Go into the adaptec bios (ctrl-a on
bootup), and fix the sync speed, or the negotiation speed.. Whichever they call it.

That'll make a big difference to equalizing the machines.

Mike Dresser