Macos – Upgrade 2006 iMac to install El Captain

Warning: Most knowledge here is theoretical, and needs to be backed up with facts based off specific needs

You probably could/should set up a cluster. If you're going for new systems, the cheapest multicore systems sounds like a good bet (if you go for old ones AVOID PENTIUM IVs, unless you want to heat the room more efficiently than you process. I would consider a dual core 2 ghz system slightly better than a single 4 ghz processor, unless you had a single thread that requires a lot of power (which you don't). I'd note that in general, newer versions of mainstream processors do generally tend to be better than the ones they replace, especially recently since power use has become an issue.If i wanted to get down to the nitty gritty of it, i'd look at the various generations of processors, and benchmarks for them to get a clearer idea of efficiency and power.

You'd probably want to consider booting the worker systems with a minimal os, off standard images via network using PXE to save on storage for each individual system - since your ram requirements are minimal, you could probably have the entire OS in ram, since you're only using it for one thing

You would need to probably have software that is capable of being run on a cluster (IE, take that into account when designing it - maybe with MPI, have the cluster software setup and so on. That being said, i have seen MASSIVE arrays of commodity PCs linked together at a university for a cluster so its plausible

On the other hand, considering massive parallelisation is your main goal, and you're going for massively parallel workloads , you might want to consider alternatives to a x86 cluster - ubuntu has a 48 core cluster that they built out of arm development boards (I'm thinking a cluster of raspberry pi systems would be... interesting, and quite efficient powerwise, if you didn't mind a massive array of odd little inexpensive systems).

The NITU1 motherboard supports only FSB800 Processors. I would recomend using any Penyrin processors that support FSB800. I would recomend using the T8300. The max that you could possibly do is T9500 CPU and 6GB Ram @ 1066.