Amazon says their "m1.small" instance has 1.7 GiB of memory. That's a lot less than most current laptops. Maybe JRuby uses more memory in total, but can handle

Amazon says their "m1.small" instance has 1.7 GiB of memory. That's a lot less than most current laptops. Maybe JRuby uses more memory in total, but can handle more concurrent requests per MB of memory used? That could explain the discrepancy if it's true, though it's just speculation on my part. Another theory is that the benchmarks are too application-specific. Rails is a complex framework with which you can build many different kinds of applications, each with its own performance characteristics. Conceivably, application A could perform better on JRuby, while application B could perform better on MRI. Depending on which application you use for your benchmark, either interpreter could appear faster. This calls into question the utility of benchmarking an entire framework. It might be better to do micro-benchmarks, with each one testing a specific scenario. Scenarios could include, for example: A request that loads 1,000 database records into memory; a request for a static image; a request that queries a many-to-many relationship; a request that saves an uploaded file to disk.