🚀 go-pugleaf

Your points are good.  I've been discussing workstation HD performance. The
thread title includes "EIDE" which implies workstation and not server
usage.

Chris Kennington - newshound <Newz@inf-eden.demon.co.ux> wrote in article
<881691095snz@inf-eden.demon.co.ux>...
> In article <348c422b.31666353@news.demon.co.uk>
>            bob@lintilla.demon.co.uk "Bob Cousins" writes:
> 
> ">Workstation performance is dominated by sustained transfer rate and not
> ">access time.
> "
> "I think that's completely untrue. Only in very few situations do you get
> "conditions where sustained transfer rate would be dominant. [snip]
> 
>     I've been reading the part of this thread to do with access
>  rather than EIDE/SCSI in a somewhat bemused fashion.  Let's skip
>  the parts that are to do with stand-alone systems (most of the
>  posters are discussing servers), and think about the dominant
>  factors in a network data transfer.  All this work was done in
>  CompSci departments in the 1970s (if not 1960s).
> 
>     It is really not safe to say that any one factor is dominant
>  in determining average transfer-rates, except in tightly defined
>  circumstances.  I have not noticed a single post discussing the
>  effect of two simultaneous transfers (of different data), or of
>  network bandwidth limitations, etc.  The effects of
>  'disk-thrash', 'ethernet degradation' etc can be massive.
>  (Frinstance, in the early days of classroom networks, where a
>  single pupil could download the software in 20 seconds, it could
>  take 30 minutes for a class of 10 to do so if all started
>  simultaneously.)
> 
>     In general terms, in any situation where there are likely to be
>  simultaneous transfers going on, putting reasonable figures into
>  the calculations is likely to show that transfer-rate will be
>  improved more by massive buffering, read-ahead logic and large
>  logical packets on the LAN than by speeding up raw disk-to-RAM
>  transfer rate.  The concept is to do quite a lot of one thing
>  before you switch to another, rather than switching frequently.
>  The major loss of time is associated with changing from one thing
>  to the next.  (Consider the well-known effect on car-traffic-flow
>  of making traffic-light cycle-times longer.)
> 
>     Where's my flame-proof vest?
> 
>                                                 Chris K.
> -- 
> Chris Kennington (newshound)                        01491 574065
>   You can mail me with suitable modifications to header-addresses,
>    or to "chris <at> inf-eden.demon.co.uk", replacing the <at>.
> 
>