Well, this is fun. Here's the configuration:
- Joyent Accelerator 64-L -- We stripped it down and built it back up with the bare minimum Blastwave packages we need to run our apps (surprisingly few).
- Rails 1.2.2 Application -- Moderate DB complexity, loaded with fixture data, and using actsasferret extensively. No optimization at all (caching, query tweaking, etc.).
- Mongrel 1.0.1 -- Running in production mode as a cluster with 4 instances (I think the server has 4 processor cores).
- nginx 0.5.14 -- Built from scratch, and running the generic Rails/Mongrel configuration found on the wiki.
- PostgreSQL 8.1.4 -- Out of the box configuration from the Blastwave package (nothing special, no ANALYZE statements).
Not bad .. but the big fat caveat is that it's 11:00 PM so our box obviously isn't loaded very heavily. We can burst up to 95% CPU utilization on the machine, so of course these numbers don't reflect reality of peak hours. That said, we've never seen load reported over 0.2, even during peak.
Update: I should note that the 50/sec rate is for a pretty dynamic application with some bells and whistles; connections for static content are in the hundreds per second, but not too applicable for our purposes.