From mboxrd@z Thu Jan  1 00:00:00 1970
From: erik quanstrom <quanstro@labs.coraid.com>
Date: Thu, 18 Aug 2011 01:29:29 -0400
To: 9fans@9fans.net
Message-ID: <afa907c3be69717b86a41caafe955006@coraid.com>
In-Reply-To: <20110817210038.66E0CB827@mail.bitblocks.com>
References: <CAEAzY3_Vx8WW1Oumt0t1_Ay6LtpTFFonpwMD+=0DYCM-yxXaeA@mail.gmail.com>
	<20110817210038.66E0CB827@mail.bitblocks.com>
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Subject: Re: [9fans] Help with two small shared file servers
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> > Is 9p suitable for this? How will the 40ms latency affect 9p
> > operation? (I have 100Mbit).
>
> With a strict request/response protocol you will get no more
> than 64KB once every 80ms so your throughput at best will be
> 6.55Mbps or about 15 times slower than using HTTP/FTP on
> 100Mbps link for large files.  [John, what was the link speed
> for the tests in your thesis?]

i calculate 1/0.080s/rt * 64*1024 = 819 kbytes/s.  (i think your
conversion from mbits/s to bytes/s is faulty.)

also you do get 1 oustanding per read or write, not per machine.
so the real limit is wire speed, but for most programs most of the
time the limit for a single file transfer would be as you specify.

- erik