There is no single fit for all. You have to play around to get your size.
A good place to start reading is
https://wiki.mikejung.biz/Fcgid
http://2bits.com/articles/apache-fcgid-acceptable-performance-and-better-resource-utilization.html
If that is too much geek or cumbersome, just get a good webhost.
Hi,
This is a fastcgi or php-fpm error. You need to tweak the php parameters to correct the issue.
