Here are some tips to help boost the performance and speed of your Magento store:
Disable Access Time Logging
For Linux servers, if you have access-time logging enabled on any of your mysql, web server or cache partitions, you might want to try turning it off for a performance boost. If you’re using ext3 or reiserfs there may be faster journal write methods you can use. For more information go to Linux.com.
Enable KeepAlives in Apache
Memory Based File Systems
Are you using a memory-based filesystem such as tmpfs? These help Magento move faster because of all the reads/writes. Magento makes extensive use of file-based storage for caching and session storage. One of the slowest components in a server may be the hard drive, so if you use a memory-based filesystem such as tmpfs, you can save on all those disk IO cycles by storing these temporary files in memory instead of storing them on your hard drive.