Bluehost.com and Hostmonster.com have a CPU quota limit in place to try and mitigate the server problems that a single user or a small set of users can create. This is custom software that we have written ourselves. I know of no other shared host that has this ability to limit cpu quota by user for Linux.
The problem has been that our software was written at a time when single or dual cpus were the norm. This was the case when Bluehost first started. However, our current servers have at least 8 cpu cores. Most of our cpu intensive software is also multi-threaded and can be effectively distributed across multiple cpus effeciently.
Because modern cpus in general have more cores, run at a lower frequency, and most of our hosting software is designed to run in this type of environment it has become VERY apparent that we needed to update the way we calculated “cpu usage”.
Effective immediately (Actually as of Friday January 25th) we have altered the way we calculate CPU usage. Each user’s cap is now approximately double what we had it set to previously. Many users have complained lately that our cpu quotas were overly restrictive. I believe these changes should reduce the number of people that run into this problem by about 90%. We will continue to tweak our settings to stop only the most abusive of users on the system. This was never meant as a way to limit functionality, but rather a way to guarantee resources for servers that are shared by many users.
This should make life MUCH better for those users that have been bumping up against this limitation.
Matt Heaton / President Bluehost.com – Hostmonster.com