cgi php better for apache2 than mod_php?

[togbenson]

While doing some load testing, I found it was not difficult to make my apache2 server running mod_php5 hang.  In fact the whole server would come to a crawl (running "ls" in a shell was hanging).  Yet the server was only using 200 mb of ram (out of 650).  There was no thrashing as far as I could tell.

 

I switched to cgi php and while each php page execution time increased apache can handle much bigger loads.  I can even load it up so that it's using 450 mb and it still (albeit slowly) responds to requests.

 

I am confused.  I thought mod_php was just better.

 

Thanks,

Tog