[comp.sys.next] floppy disk IO SLOW using DOS disks.

streib@silver.ucs.indiana.edu (Allan Streib) (04/27/91)

I have noticed that copying files to/from a DOS floppy takes many
times longer than the same action using a UNIX floppy.  It's also much
slower than floppy IO on a PC.  Why is this?  It is really almost
frustrating. 

-Allan

timbuck@wookumz.gnu.ai.mit.edu (Timothy Buck) (04/28/91)

In article <1991Apr27.060720.17542@bronze.ucs.indiana.edu> streib@silver.ucs.indiana.edu (Allan Streib) writes:
>
>I have noticed that copying files to/from a DOS floppy takes many
>times longer than the same action using a UNIX floppy.  It's also much
>slower than floppy IO on a PC.  Why is this?  It is really almost
>frustrating. 
>
>-Allan

This is because it's not just copying files -- it has to do conversion from
DOS to Unix format in the process.  I don't know the technical details, but
that's what's going on.

Tim

jjb@hardy.u.washington.edu (Jim Black) (04/28/91)

In article <15367@life.ai.mit.edu> timbuck@wookumz.gnu.ai.mit.edu (Timothy Buck) writes:
>In article <1991Apr27.060720.17542@bronze.ucs.indiana.edu> streib@silver.ucs.indiana.edu (Allan Streib) writes:
>>
>>I have noticed that copying files to/from a DOS floppy takes many
>>times longer than the same action using a UNIX floppy.  It's also much slower
>>than floppy IO on a PC.  Why is this?  It is really almost frustrating. 
>
>This is because it's not just copying files -- it has to do conversion from
>DOS to Unix format in the process.  I don't know the technical details, but
>that's what's going on.

It doesn't seem to me that it's because of internal UNIX<->DOS file 
translations (eg, cr/lf <=> lf), because the delays are bad with pure 
binary files.  It's a real drag, it almost makes a joke of the inter-media
compatibility.  
--
Jim Black  (jjb@u.washington.edu)