[eepro100] TCP_RR rate, 21143 vs 82559

[Kallol Biswas]

Hi,
   The netperf TCP_RR transaction rate for 82559 is considerably lower
than the 21143 for short packets. However for big packets
82559 performs better than 21143. The I/O bursts from 21143 are not
larger than 8 cycles even if other device is not present on the bus, whereas
82559 does not relinquish the bus before completing the entire transfer. This
might cause 82559 card to have better transaction rate for bigger
packets.

21143 is around 15% better than 82559 in terms of 
transaction rate for the TCP_RR packet size of one byte, but around 8%
worse for a packet size of 1500 bytes. The break even size if around 900 bytes.

Probably the real problem with short packets 
lies in the design of the 82559 card.

Any comment is appreciated.


BTW, our lab is shutting down, and I am looking for a job. My resume
is at: http://resumes.dice.com/kallolbiswas

Kallol


Phone: 973-443-7469         |  Design Engineer
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