I am curious what should be the benchmark for making the choice of switching from 32bit to 64bit Linux? I have a few assumptions below. Is my logic sound? (This is a follow up to the "Adding RAM" thread) Assumptions: 1. 4GB Memory. The main benefit of 64bit mode is the ability to address more than 4GB of RAM. I assume that you use 64bit mode if you want to *efficiently* have more than 4GB of RAM, or intend to upgrade past 4GB in the foreseeable future. (I emphasize "efficiently" because PAE is an option, if you are desperate to keep 32bit mode with more RAM) 2. Overhead. It is my assumption that 64bit has more "overhead", being that the registers are now 64bits long, instead of 32bit, which would mean more bits to pass around the system. So if you have less than 4GB of RAM, 32bit mode would perform better than 64bit mode. 3. Compatibility. Linux has made incredible strides to make 64bit Linux very robust and compatible, but I still occasionally see binary applications/plugins/drivers that popup which are 32bit mode only. This is usually only a problem with Desktop systems that want bleeding edge, or not as well supported software. 4. Desktop vs Servers. Current "desktops" machines generally have around 2GB of RAM, or less. Current "server" machines generally have around 2GB of RAM, or more (much more). Because of the overhead (#2) and compatibility (#3) I would think that Desktops would benefit from using 32bit mode, and Servers would benefit from 64bit mode. Is my logic sound? Thanks, Kenneth