General Setup | Advanced Setup | Performance Setup

PERFORMANCE SETTINGS
  Cache expiration time, minutes Many database queries can be cached to reduce server load. The higher is cache exp. time, the less is server load. Set to 0 to disable caching.
Setting to low value (0-10) is recommended if your website is under development, for best performance at live mode please consider higher value (30-60 and more).
  Cache size ##cache_size##  
  Cache entries ##cache_entries##
  Activate compression (gzip'ed output of PHP pages)? Check on to increase PHP pages loading speed. Gzip'ed output is supported by IE 4+, NN 4.x and Mozilla You need zlib compression support compiled in PHP
  Max. allowed keywords amount in Keywords Search Ability to limit searchable keywords amount allows to keep server resources usage reasonable. Setting to "0" value means unlimited keywords amount and is not recommended
  Show {items} amount when browsing categories in admin area Checking off may improve performance [admin area only] for large databases
  Check if the "install.php" file exists, and warn of its existence Check this option off after removal (renaming) of install.php