The biggest take-away for me is this gives you an oppertunity to (somewhat) rebalance the performance equation of the server. Currently, your typical dual-sock

The biggest take-away for me is this gives you an oppertunity to (somewhat) rebalance the performance equation of the server. Currently, your typical dual-socket, quad/six core CPU, is quite top heavy: LOTS of CPU performance, only a satisfactory amount of RAM bandwidth (and in certain cases not limited by bandwidth but by the DRAM command rate), along with piddling disk and network performance. You could create a dual or quad-core ARM Cortex A-9 chip with a dual-channel memory controller (more memory bandwidth/ops per degree of CPU performance), dual or single gigE (more relative bandwidth per node), and finish it with a single SSD (lots of IOPs). Since these nodes are fairly affordable (probably $500) and relatively low power (probably 10-15 watts, you're left with nodes that 1) offer 1/3rd the performance but are 1/5th the price and use 1/20th the power 2) can be scaled cheaply and predictability, particularly as it pertains to laying out your datacenter power and cooling infrastructure. Also, for people who don't have complete control of their data center (they're renting rack space), it eliminates a significant amount of headache finagling your datacenter to provide enough amperage to your rack, and eliminates surprise deficiencies in their cooling infrastructure.... lessons I've learned the hard way. Micro-servers let you scale at a much more granular level so that you aren't rolling out several kilowatts of servers at a time, and let you avoid carrying excess capacity as you wait to grow-into it (only to scramble to scale after you're full-up again)