I haven't done a thorough or systematic comparison, but I'd expect slightly slimmer but similar results with Sinatra apps given the 80MB figures you quote above, the rails processes were around 120MB on average, Go 6-10MB and scales without extra processes. Obviously the smaller the framework you load for each process, the less memory you're going to use, but there are also architectural differences in the languages which seem to add up to significant memory usage in the case of Ruby.
Because to scale ruby you'll typically add more processes, and to scale go you'll just let it start another thread (the http server does this for you), that difference adds up to a significant difference when you have a lot of traffic.
That's not to say that Ruby is impossible to scale and I love Ruby the language, but it is a bit slower and a bit more memory intensive than Go.
Then say Rails. Rails doesn't care about memory. There are frameworks of similar targets like Rails that tend to use less (e.g. Padrino) and care. We did have an effort pushing down unnecessary memory use of the base profile and we gained in slabs.
Also, you can move to JRuby if you want a one-process/threaded model, which will get memory-conservative very quick. A JRuby thread will quickly get you into the ranges that you quote for go + the base cost of the JVM.
The figures you quote above are better than Rails but still almost an order of magnitude worse than Go. Clearly there's something else going on. I'm not saying everyone should abandon Ruby and move to Go (and I think neither is the article), but we should be aware of the tradeoffs involved in each tool choice (Ruby, Ruby with JVM, Go etc).
You are still comparing apples with oranges. Go and even Padrino (which is a full-stack in a full blown install) are not even the same category.
Point being that memory comparison even in the Ruby/Rails space are incredibly problematic, often influenced by the runtime (and heavily so). Still, the discussion is incredibly simplistic (for example by assuming that you are running unicorn/fork).
If a discussion about memory issues does not include an exact reference to the runtime and implementation of the system used, I would consider it void immediately.
I haven't done a thorough or systematic comparison, but I'd expect slightly slimmer but similar results with Sinatra apps given the 80MB figures you quote above, the rails processes were around 120MB on average, Go 6-10MB and scales without extra processes. Obviously the smaller the framework you load for each process, the less memory you're going to use, but there are also architectural differences in the languages which seem to add up to significant memory usage in the case of Ruby.
Because to scale ruby you'll typically add more processes, and to scale go you'll just let it start another thread (the http server does this for you), that difference adds up to a significant difference when you have a lot of traffic.
That's not to say that Ruby is impossible to scale and I love Ruby the language, but it is a bit slower and a bit more memory intensive than Go.