ruby / rails / mysql performance degraded on Snow Leopard

I've burned a bunch of hours on this. I'm not having problems getting things to build, but I am seeing that my test suite runs about 2x slower than when I was on OS X 10.5.x . I've spent a lot of time playing around with different optimization settings (learning to avoid homebrew's llvm-gcc compilation). I've just learned that I needed to tweaks /Library/Preferenc开发者_StackOverflow社区es/SystemConfiguration/com.apple.Boot.plist in order to get the kernel to boot in 64 bit mode. However, my rails app is still running a bit slower than before, even after warming up the mysql server.

So what performance tweaks might i need to look into? Right now the stock ruby 1.8.7 runs faster than 1.9.1 for some things, and I'd really like to know if there is anything I should be looking for. All my dev software has been compiled for x86_64, mysql with -O2 optimization, using regular gcc (not llvm-gcc).

turned out i was being stupid. I'd added/modified a few lines in my test suite which killed the performance that I was concerned about.