Update: you can find the tarball for this script at: http://github.com/downloads/otzy007/enable-zRam-in-Slackware/enable-zram-noarch.tgz

Referring to this article it seems that using a swap disk is slower than compressing the data in the memory.

Enabling this under Slackware Linux it's pretty easy.

Create the file /etc/rc.d/rc.zram and put this script into it:

Remember to make it executable: chmod +x /etc/rc.d/rc.zram

Also copy this lines to /etc/rc.d/rc.local or /etc/rc.d/rc.M