From: rl@cbnewsl.cb.att.com (roger.h.levy)
Newsgroups: comp.sys.ibm.pc.hardware
Subject: Re: Fast hard drives - seek isn't everything.
Date: 25 Dec 92 17:12:06 GMT
Distribution: na
Organization: AT&T Bell Laboratories

In article <BzGu6r.811@sunnup.MAGDATA.COM>, beemer@sunnup.MAGDATA.COM (Oscar the Grouch) writes:
> In article <1992Dec17.092641.24824@doug.cae.wisc.edu> keiths@cae.wisc.edu (Keith Scidmore) writes:
> >
> >I asked Hard Drives Intl for their fastest IDE drive (thinking I would
> >let Zeos keep the Seagate 3283A 245MB drive that came with my system 
> >and upgrade immediately).
> >HDI sent me a $1000 FJ2624A 510MB Fujitsu IDE drive.x
> 
> So they sent you what you asked for the disk with the fastest published specs.
> 
> >It turned out to be slower than the Seagate on
> >all the benchmarks and programs I tested even though it had about
> >an 8 ms seek time to the Seagate's 11 ms.  The following explains
> >how this was determined and why the Seagate was faster on both
> >the benchmarks and on real programs.
> >
> >The Seagate was 10-20% faster than the Fujitsu on all my program test.  The 
> >reason is that the Fujitsu drive was about 18% faster on seek times but the 
> >Seagate was about 50% faster in transferring the data.  I returned the 
> >Fujitsu to HDI.
> >
> 
> So who paid for your learning experience. Sounds like HDI did.
> 
> >First, transfer speed is significant in
> >choosing a drive.  The Fujitsu's 8 ms average seek time (measured) didn't 
> >make it faster.  The Fujitsu should have had the additional advantage in that
> >the software on the larger disk takes less of a percentage of the platters
> >and the seeks should have been a smaller percentage of the total stroke.
> >
> >Second, HDI doesn't always know what they are talking about.
> 
> What they told you was what you asked for the published stats.
> 
> >They were inaccurate in telling me the stats of both drives.  My tests
> >showed that the Seagate Drive on my Zeos 486-66 VLB machine ran faster 

> So let me guess, after installing the disk, beating hell out of it with
> your testing program, and using it for some unmentioned period of time 
> you returned it for a full refund. Not; because the drive was defective.
> Not because it did not meet the published specs. but because it did not
> live up to your expectations.

I agree that Keith has abused HDI's highly customer oriented policies.
Also, Keith hasn't said enough to convince me that his testing was
well controlled.  The fact that he didn't previously even understand
the signficance of rotational latency casts a lot of doubt on his ability
to insure that all other factors were equal.  For example, the specs I
have say the Fujitsu has a segmented 240KB read-ahead cache that "can
be configured to further optimize drive performance and [provide] even
faster data throughput."  Did you take a look at configuring the cache,
Keith?  At 4400 RPM and a rotational latency of 6.8 msec, the Fujitsu
drive SEEMS to have been engineered with transfer rate in mind.  I am
more impressed by HDI's recommendation and the fact that Box Hill selected
the SCSI version of this drive for their RAID systems than I am with
Keith's apparently uninformed poking around.

Roger Levy
Murray Hill, NJ
Newsgroups: comp.sys.ibm.pc.hardware