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Subject: Re: Disk perf. with different HDs/Adapt.
To: bde@zeta.org.au (Bruce Evans)
Date: Mon, 26 Feb 96 18:16:25 MET
From: Greg Lehey <lehey.pad@sni.de>
Cc: hackers@freebsd.org (Hackers; FreeBSD)
In-Reply-To: <199602240722.SAA23535@godzilla.zeta.org.au>; from "Bruce Evans" at Feb 24, 96 6:22 pm
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>> Those 1.92 seconds make for exactly 6826667 Bytes per second ...
>> And the 7.43 give some 6962656 Bytes/s.
>
>> (Yes, I know, the results aren't exact to more than 2 decimals
>> due to the limited time resolution ...)
>
> Someone should fix dd to use the available resolution of 4-6 decimal
> places.  I suppose the output of `time' is too standard to change.

How about a high-resolution option.  For example,

 # time dd if=/dev/rsd0a of=/dev/null count=200 bs=64k
 13107200 bytes transferred in 2 secs (6553600 bytes/sec)
 1.92 real         0.01 user         0.05 sys
 # time -h dd if=/dev/rsd0a of=/dev/null count=200 bs=64k
 13107200 bytes transferred in 2 secs (6553600 bytes/sec)
 1.920317 real 0.009387 user    0.0512614 sys

Greg