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From: harald@ccicpg.UUCP ( Harald Milne)
Newsgroups: comp.sys.amiga
Subject: Re: Amiga NFS
Message-ID: <3178@ccicpg.UUCP>
Date: Tue, 20-Oct-87 05:01:54 EDT
Article-I.D.: ccicpg.3178
Posted: Tue Oct 20 05:01:54 1987
Date-Received: Wed, 21-Oct-87 06:38:12 EDT
References: <8710182253.AA05929@cory.Berkeley.EDU>
Organization: CCI CPD, Irvine CA
Lines: 46

In article <8710182253.AA05929@cory.Berkeley.EDU>, dillon@CORY.BERKELEY.EDU (Matt Dillon) writes:
> 	Thus, the slowness one experiences with HARD DRIVES is probably due
> to an inefficient layout on the HD.  DOS has a bad habit of putting it's
> sector lists far away from the data sectors themselves, causing lots of 
> seeking when reading (two seeks every 32K ... yuccc!!!).

	Seeks! Yucc is right. Doing DMA doesn't really matter if you have
to wait milliseconds for the head to travel back and forth. I got a 20meg
supra drive, and was very unhappy in the performance. But I knew this before
I got it, I just needed mass storage at the time. (It's hard to put a 1.3meg
file on a 880kb floppy!) 

> 	An NFS to a host which uses a good layout can be *much* faster!
> E.G. and NFS to a SUN or VAX host.

	I thought about this a little more, and I realized that the Amiga
running as a client to a host file server wouldn't have to deal with DOS!
There is no Amiga anything on the other side, just UNIX. So it's just a
matter of how fast you can pump the data into memory off the Ethernet. (Well
also how loaded the server is, how much traffic on the net, etc.
Damm NFS, it's so invisible your forget it's there, much less how it
works!) With that in mind, I wonder which will be faster, the rumored
1.3 ehancement that require mount or bindrivers command (kiss the supra off,
unless they start conforming to spec's) or NFS? I'll dig into NFS bandwidth.
Offhand it look's close. That's assuming 150kb. Any developers care to comment
since CATS can't.

	While on the subject of harddisks, I am doing simulations of SCSI
drives on UNIX, and found out that SCSI drives will buffer a track, unless
you hit it with another seek request in which case it aborts and does a seek.
Yucc! The buffering only helps if your next request is on the same track,
which in the case of UNIX read ahead works sometimes. Add to the headache
that UNIX only feeds sorted seek requests one at a time to the driver, the
file system has to be modified. Oh well!

	I am spoiled to the power of my company's UNIX systems, so mention
of Suns or Vaxs tend to make cringe, no offense. I guess that's considered
a plug, so disclaimer here. I am getting the Ameristar A2000 Ethernet card,
which is why I brought all this up. If anyone is interested, I can post
throughput of file transfers, on unloaded file servers.

	Special thanks to Matt!
-- 
Work: Computer Consoles Inc. (CCI), Advanced Development Group (ADG)
      Irvine, CA (RISCy business! Home of the CCI POWER 6/32)
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