IDE Drives

[Dave McLane]

rreiner at yunexus.YorkU.CA (Richard Reiner) writes:

> lam at hyper.hyper.com (Edmund C. Lam) writes:
>
> >The drawback with IDE comes from the fact that the interface limits
> >your data transfer rates to an observed maximum of 400K/s.
> >The drive might be quick on average access time, but IDE drives
> >suffer from low transfer rates.
>
> As a generalization, this is false.  I have observed 950 Kb/sec from
> IDE drives on ISA 386-33 machines.

For what it's worth, I spent some time investigating whether to use
"IDE" or "ESDI" before I got my UNIX box (Dell 333D with 320 MB
ESDI).  The conclusion I came to is that one cannot make any kind
of intelligent decision based upon the names; instead you need to
know both the average seek time *and* the transfer rate.

My simple minded comparison test to concatenate a 96 K file 8 times
to make one 768 K file took the following times:

   80386 SX 16 Mhz with  40 MB IDE   7.5 Mbps controller: 10 sec
   80386 SX 16 Mhz with 190 MB IDE  14.8 Mbps controller:  4 sec
   80386 33 33 Mhz with 320 MB ESDI 20   Mbps controller:  2 sec

Kinda makes sense if you look at the Mbps, doesn't it?

--Dave