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Date:      Thu, 15 Jun 2006 14:57:52 -0400
From:      Charles Swiger <cswiger@mac.com>
To:        Paul Marciano <pm940@yahoo.com>
Cc:        freebsd-questions@freebsd.org
Subject:   Re: fxp driver performance expectations
Message-ID:  <8A5A6474-58E1-43EB-88DF-9C7E69DECF13@mac.com>
In-Reply-To: <20060615182540.43537.qmail@web54009.mail.yahoo.com>
References:  <20060615182540.43537.qmail@web54009.mail.yahoo.com>

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On Jun 15, 2006, at 2:25 PM, Paul Marciano wrote:
> For larger packets (e.g. 700 bytes) I am getting
> 100Mbps throughput port to port.
>
> For min-size packets (64 bytes) I am only seeing
> around 60Mbps.  Increasing HZ and the polling
> parameters does not help.

You should be aware that the minimum 64-byte packet size does not  
count the 8-byte ethernet frame preamble (well, 7 bytes of preamble  
and 1 byte called the "start frame delimiter"), which means that  
you'll only be able to get a theoretical maximum of about 87 Mbps of  
packet data through at the 64-byte packet size.

-- 
-Chuck




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