Tornado twice as fast with PyPy 1.7 compared to Python 2.7

I <i>love</i> PyPy, but it kind of sucks watching everyone get excited about the CPU performance of a web server while forgetting about this:<p>"Pypy used about three times as much memory in both cases, but usage was stable over time (i.e. it's not "leaking" like pypy 1.6 did)."<p>For a front-end web server, I'd trade CPU perf for memory any day of the week.

While I've also seen it to be about twice as fast in my own testing (not with Tornado), it also had much longer GC pause times. (No stats, just watching my program's logs go by -- very noticeable stutters every couple seconds or so.)

And memory stable!<p>And three times faster on template rendering!

It's interesting that the first run on both the PyPy tests was significantly slower than all subsequent runs. I guess PyPy needs to do a bit of work before it's properly warmed up.