🚀 go-pugleaf

    I was just looking through a flyer annoucing disk drive upgrades
    for DN3xx, DN5xx, and DN3000 nodes. The technicals specs lists the
    new 190Mb for the DN560/570/580 as having a transfer rate of only
    .625 Mb/sec -- slower than the .806 Mb/sec transfer rate of the 70Mb
    drive on the DN300/320/330 and *much* slower than the 10.0 Mb/sec
    rate of the DN3000 disks. Is this a misprint? Why would the high-end
    workstations have the slowest disk drives and the low-end workstations
    have the fastest disks?

I believe the following summarizes the actual situation.  Also, I think
somewhere along the line you may have confused bits/sec and bytes/sec.
Anyway, I am told that as far as the read time goes, the average read
turns out to be faster on the newer machines.  Only in sequential tranfers
does the transfer rate advantage of the DN300 family drive have any effect.

Here's the data:

                 33/70MB SMD  86MB ST412/506  190MB ST412/506 170/380MB ESDI
  DN300               X
  DN3000                             X                             X
  DN5x0                              X                X             
  DN5x0-T (Turbo)                                     X            X


  Interface         Transfer rate        Capacities       Average Seek time
  
  ST412/506          .625  MB/sec        86MB  190MB        28 milliseconds
  ESDI              1.25   MB/sec       170MB  380MB        28 milliseconds
  SMD (DN300 drive)  .8    MB/sec        33MB  70MB         42 milliseconds


(Thanks go to Joe Wadleigh for getting me this data.)

                -- Nat Mishkin
                   Apollo Compute Inc.
-------