SQL*Net performance

I found some puzzling performance difference between using the SQL*Net tcp/ip driver and the pipe driver. We ran a little sqlplus script that does a select on a large table, it runs at least twice (usually 3 or more times) slower if we specify the T:xxx compared to the pipe driver. The amount of data returned by the select statement was insignificant. Since most of the work is done in the oracle server side anyway, why would the connection method matter? Is there some kind of tuning I could do to improve the sql*net performance?

Our environment: Oracle RDBMS 6.0.33.1.1 on Sun 4/470 running SunOS 4.1.1B

Viet Hoang
AT&T Denver Works
v.q.hoang_at_att.com

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Viet Hoang
AT&T, Denver Works
v.q.hoang_at_att.com