> What do you get when outputing to /dev/null?
> What if you access the database with "localhost:/data/testblob/01.fdb"?

Same result on both

time /opt/firebird/bin/isql -u SYSDBA -p masterkey /tmp/rep1024.fdb -i
inputfile > /dev/null

real 1m36.744s
user 0m0.087s
sys 0m0.076s

time /opt/firebird/bin/isql -u SYSDBA -p masterkey
localhost:/tmp/rep1024.fdb -i inputfile > /dev/null

real 1m36.735s
user 0m0.085s
sys 0m0.080s

> Have you tried using Linux isql to access Windows Firebird
> and vice-versa?

This shows an unexpected result:

Linux isql -> windows server: 42 seconds (as expected)
Windows isql -> linux server: 36 seconds (not as expected)

>
> Which tool have you used to insert data?

A test program using firebird.net provider. Indeed we thought it was the
provider, with a different implementation for windows and linux that had the
problems, but discarded after testing with isql.

As a curious result, firebird embedded server in linux shows same speed as
windows embedded. Firebird windows server is twice as slow (which is what
one'd expect, as it uses network protocol instead of direct library calls).
However, firebird server is between 15 and 20 times slower than linux or
windows embedded.