A low-cost, high-density mounting system for computer clusters

As the number of the processing units in a cluster computing system increases, what once were inconsequential details become major engineering concerns. Space, power distribution, and heat dissipation each demand attention for such clusters. We describe a simple rack mounting system that serves as a low-cost solution for clusters with fifty or more machines. Four motherboards of the same form factor are linked together with threaded rods and spacers and hang from inexpensive shelf brackets. This approach has enabled us to mount forty-eight motherboards and additional support hardware on a 6.5ft mobile rack with a 27in x 32in footprint for a fraction of the cost of traditional computer rack equipment or standard cases. In addition, the sharing of power supplies by eight motherboards has dramatically reduced complexity of our cluster. Efficient heat dissipation is demonstrated by thermal imaging.