Also to add to the article: I have also discovered that for our deep learning workloads 8 core VMs are the sweet spot in terms of cost/perf. This is on Google Cloud, which in the particular zone I tested uses $5k apiece high end Broadwell Xeons with tons of cache. Our stuff is quite a bit faster than general purpose frameworks like TF though. 8 cores is not as fast per core as the smaller number of cores, but latency is lower, and the penalty per core is not that bad. After 8 cores perf per core drops off pretty steeply due to memory bandwidth constraints. I imagine PPCle would be pretty awesome with its 250GB/s of memory bandwidth. I wish I had a machine to try out.