Mad 5.5 performance on identical servers

[Peter Konrady]

Hi,
we have got 2 machines, both identical in hardware.

16x CPU, 24 GB RAM, identical disks

First machine was installed by a run-away admin.
Second machine was installed/upgraded by me.

Both machines deliver diverting sysbench results by a factor of 3.

Who can say why is this?
Of course the my.cnf settings are the same on both installations.


More info:

Machine 1:
-------------
Debian Lenny, MySql 5.0: transactions: ca. 3600 transactions/sec


Machine 2:
-------------
Debian Squeeze, MySQL 5.5: transactions: ca. 1300 transactions/sec


When I run the tests, I see the CPUs utilized at 30-40 % level. The second machine uses only 7-15% CPU running identical tests.


Tests run:

sysbench --test=oltp --oltp-table-size=1000000 --mysql-host=xxxx --mysql-db=test --mysql-user=root --mysql-password=xxxx --max-time=60 --oltp-read-only=on --max-requests=0 --num-threads=8 run



regards,

Peter