As of the 25th of December, 2019 we have a released version of Ruby 2.7.0. As you can read in the title - it’s basically the same as 2.6.0.
The 2.7.0 series is remarkable in how little the speed has changed. Overall it has been very stable with very little change in performance. I’ve seen a tiny bit of drift in Rails Ruby Bench results, sometimes as much as 1%-2%, but no more.
The other significant news is also not news: JIT performance is nearly entirely unchanged for Rails apps from 2.6.0. I don’t recommend using CRuby’s MJIT for Rails, and neither does Takashi Kokubun, MJIT’s primary maintainer.
I have a lot of data files to this effect, but… The short version is that, when I run 150 trials of 10,000 HTTP requests each for 2.6.0 versus 2.7.0, the results are well within the margin of error on the measurement. With JIT the results aren’t quite that close, but it’s the same to within a few percent - which means you still shouldn’t turn on JIT for a large Rails app.
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