Subject: performance
To: None <amiga@NetBSD.ORG>
From: Calvin <diavolo@azure.engin.umich.edu>
List: amiga
Date: 11/09/1995 03:01:33
I'm using a Deringer 25, A2000.  2091.  netbsd 1.0

dd bs=2500000 if=/dev/zero of=/dev/null count=45

I was trying to get an idea of how fast the machine can push around the 
i/o just within memory.  i get a value of 2 megs per second if there is 
another program running.  4.5 megs per second if only dd is running.  
does this sound right or is this terribly slow? bs=2500000 withstanding.

then i went and tunefs'd the rotational delay to 0 and i tried:

dd bs=2500000 if=/dev/zero of=/tmp/foobar count=2
5000000 bytes in 92 secs (~50K/sec)
dd bs=4096 if=/dev/zero of=/tmp/foobar count=1220
4997120 bytes in 50 secs (~100K/sec)

how do I explain this to myself?  i'm waiting for netbsd 1.1 to come out, 
and i'm hoping for some much improved performance of some kind from the 
improvements made.  :)  i am wondering tho, how is it possible for the 
disk performance to approach a meg a sec even, if the cpu can barely push 
2 megs per second in ram under a light load?  

--
 o/ \o/  o  <o   o  o   o    She walks in  beauty, like the night
<|   |  /|\  |> <|><|> <|\       Of cloudless climes and starry skies;
/|  / \  /| / \ //  \\ / \   And all that's best of dark and bright
""""""""""""""""""""""""""""     Meet in her aspect and her eyes.  (Byron)