Things to tweak on your Magento installations gleaned from the Magento forums.
Magento ver. 1.0.19870.4
Install APC
# pecl install apc
edit php.ini to use apc extension
extension=apc.so
Switch mysql query caching on in my.cnf
query_cache_size=32M
uncomment sections of Magento’s .htaccess file to activate http compression (deflate).. starting here…
SetOutputFilter DEFLATE
add the following to the global section of the /app/etc/local.xml
<cache>
<backend>apc</backend>
<prefix>alphanumeric</prefix>
</cache>
Disable these System -> Cache Management sections in Magento Admin
References:
http://www.crucialwebhost.com/blog/improving-magento-speed-and-performance-with-mysql-query-cache/
