I have noticed that when I lightly load my rails virtual host with a simple 'ab -n 30 ', the railsrunner seems to take about 40-70% of the user cpu, while when I load my php vhost hitting the title page of my blog, it hovers around maybe 15-30% of user CPU. could it be that the rubylsapi library "spins" while ruby goes off to get stuff from the database. I can only see that it is using usleep(), so it shouldn't really be spinning. question is, is this the rubylsapi or is it because ruby is a cpu hog? how can I determine which part is being the cpu hog?