What Xoreax IncrediBuild does is perform a distributed compilation of your C & C++ source files across multiple computers connected via a TCP/IP network - even 802.11b WiFi, even a 56Kbps modem - running Microsoft Windows NT, 2000 or XP - essentially, any Microsoft OS that has the ability to run services in the background that's connected to a network. The incredible part of this - absolutely no puns intended anywhere within this review - is that it can do all of this on machines that do not have Microsoft Developer Studio installed.
For all of this to work Xoreax recommends a minimum of a 200MHz Pentium with 64MB of RAM but I'm sure most game development studios these days would be hard pressed to find a machine that underpowered actually doing any useful office work. A single machine with Microsoft Developer Studio 6.0 along with the Xoreax IncrediBuild DevStudio Add-in installed is all that's required for a development machine, Agents on remote machines and the Coordinator do not require DevStudio to be installed forgoing both the expense of an un-used software package and the requirements of a capable machine. This removes any maintenance headaches that would be caused by ensuring that the same version of compiler, libraries, header files and Service Packs are installed on a diverse network. This also means that the IncrediBuild Agent can be placed on to office machines that are not directly involved with development.
IncrediBuild performs its magic by sharing out the compilation of source files to individual machines running the IncrediBuild Agent. A source file is considered atomic, no further subdivision of labour in compiling it is possible, so the more source files in a project, the better the performance gains witnessed.
Each IncrediBuild Agent, and there can be up to 100 Agents in a build farm though 40 is the recommended maximum, creates a small cache on the HD, and, utilising spare CPU cycles - it runs at the "Idle" priority by default - compiles C & C++ source files just as though they were being compiled on the machine that's running Microsoft Developer Studio. Should an Agent detect that the host processor usage has spiked from user interaction it stops processing and informs the IncrediBuild Coordinator to find another Agent to perform the work. Considering that powerful desktop machines sit idle most of the time, waiting for the user to press another key or move their mouse, there are an awful lot of wasted CPU cycles hovering around, completely under utilised.
