Another caching engine for drupal is APC, http://drupal.org/project/apc before you install module you need to install it on you linux. And before you install APC you need to install some other dependencies, otherwise you will get errors.
So you need to run
install make
install libpcre3-dev for debian and install pcre-devel for ubuntu
and maybe also install build-essential and php-pear if you dont have it alreadythen finally you run
sudo pecl install apcand there you should have all the files installed. You need to add just one line of code to your php.ini file "extension=apc.so" and then you can check over phpinfo() and you will see if it is running ok.
For the rest take a look at the drupal APC module readme file and do what is said there and you should be good for starters.