> Date: Fri, 5 Mar 2004 13:19:03 -0600 (GMT-06:00)
> From: "Julian Wolfe (FireflyST)"
> To: Johnny Billquist
> Subject: Re: Power requirements?
>
> -----Original Message-----
> From: Johnny Billquist
> Sent: Mar 5, 2004 1:13 PM
> To: Christopher Zach
> Cc: Julian Wolfe ,
> Bill Gunshannon , info-pdp11@village.org
> Subject: Re: Power requirements?
>
> On Fri, 5 Mar 2004, Christopher Zach wrote:
>
> > RL02's spin at 2400RPM. RK05's spin at 1800RPM IIRC. Thus the transfer
> > time for data is a bit faster on the RL series drives.

>
> Transfer rates, sure. But I thought we said spinup time. Having to reach a
> lower RPM should also make it faster to come online. In short, the RK05
> takes less time to come online from the moment you push the run button.


Transfer rate is the product of angular velocity and data density.

RK05: 1500 rev/min * 12 sectors/track * 512 bytes/sector * min/60 sec
= 154 kB/sec

RL02: 2400 rev/min * 40 sectors/track * 256 bytes/sector * min/60 sec
= 410 kB/sec

Just as a reminder of progress, slow SCSI is 5000 kB/sec.
Fast SCSI is faster.

carl
--
carl lowenstein marine physical lab u.c. san diego
clowenst@ucsd.edu

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