Re: Poor performance of MySQL 5.5

[Vladislav Vaintroub]

in case you do many insert outside of transaction, innodb_flush_log_at_trx_commit=1 will force all tiny log records directly to the disk. Unless you're application is processing something extremely important like credit cards or so where in no case you can report success until the data hit stable media, you can almost safely use innodb_flush_log_at_trx_commit=2. Data reaches the disk platters safely after every second, so you can lose as much as last second of your operation if OS crashes.

Also ensure write cache on the disk is enabled. If not, then every write operation (even those for which direct write is not important for transactional integrity) will go directly to the disk.