Path: utzoo!attcan!uunet!super!udel!rochester!rutgers!tut.cis.ohio-state.edu!unmvax!pprg.unm.edu!hc!ames!lll-tis!oodis01!uplherc!esunix!blgardne
From: blgardne@esunix.UUCP (Blaine Gardner)
Newsgroups: comp.sys.amiga.tech
Subject: Re: 2090A speed
Message-ID: <1154@esunix.UUCP>
Date: 12 Dec 88 06:48:21 GMT
References: <9472@gryphon.COM>
Organization: Evans & Sutherland Computer Corporation
Lines: 33

From article <9472@gryphon.COM>, by jdow@gryphon.COM (J. Dow):
< In article <1135@esunix.UUCP> blgardne@esunix.UUCP (Blaine Gardner) writes:
<>Since I crashed my hard drive a couple of days ago, I took the
<>opportunity (!) to play with interleave. The results were underwhelming.
<>I preped the drive and formatted a 10 cylinder (~700K) FFS partition. I
<>did this with interleave values of 0, 1 and 2. There was no practical
<>difference between any of the interleaves. An interleave of 0 gave max
<>read speeds of 180K to 230K, interleave = 1 produced 200K to 230K, and
<>interleave = 2 yielded 218K and 238K.
<>
<>From this I have to conclude that interleave on the A2090A has virtually
<>no effect on performance. Surprising!
<>
< 
< I can think of two possible reasons for this lack of whelming performance
< changes while diddling interleave. Note that the "mountlist" interleave
< will make no difference on FFS disks. To effect a change you must hard format
< the drive. A soft format will do zippo.

The low-level or hard format on the A2090A is the Prep command, right?

I did redo the Prep (res0: mountlist entry), and FFS partitions both
with the different (matching!) interleave values.

The Diskperfa test were all done on the FFS partition. 

If Prep is not sufficient to do the "hard" format, how do I go about it
with the A2090A and a ST506 drive?
-- 
Blaine Gardner @ Evans & Sutherland    580 Arapeen Drive, SLC, Utah 84108
Here: utah-cs!esunix!blgardne   {ucbvax,allegra,decvax}!decwrl!esunix!blgardne
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"Nobody will ever need more than 64K."    "Nobody needs multitasking on a PC."