I recommend this table of latency figures for any software engineer: https://gist.github.com/jboner/2841832 https://gist.github.com/jboner/2841832 Essentially

I recommend this table of latency figures for any software engineer: https://gist.github.com/jboner/2841832 https://gist.github.com/jboner/2841832 Essentially IO is expensive except within a datacenter but even in a data center, you can do a lot of loop iterations in a hot loop in the time it takes to ask a server for something. There is a whitepaper which talks about the raw throughput and performance of single core systems outperforming scalable systems. These should be required reading of those developing distributed systems. http://www.frankmcsherry.org/assets/COST.pdf http://www.frankmcsherry.org/assets/COST.pdf A summary: http://dsrg.pdos.csail.mit.edu/2016/06/26/scalability-cost/ http://dsrg.pdos.csail.mit.edu/2016/06/26/scalability-cost/