Marks Rpi Cluster is on and off. As I type this its on. We had a few weeks of hot weather where I had the Pi's idle and when it gets a bit cooler have them going again.
I have reduced the cache on all of the Pi's so that I can finish off what work they have quickly. With the reduced cache they will fetch additional work only when they are about to complete the 4 tasks they have at the time.
In other news I got a few of these:
They are ASUS C2500's. They are a USB type A to RJ45 network adapter that gives 2.5GbE network connectivity. This allows me to improve the network speed on the support Pi's. I have a 2.5GbE switch on the way as well.