SHARED SERVERS:
Magic Web India allows a maximum of 25% CPU usage limit. You may exceed this limit for no longer than 90 seconds.
It is unlikely that you hit the 25% CPU usage. Unless your site is script intensive and requires more processing.
Here are some valuable tricks to lessen your CPU usage.
Reduce your number of banners and ads from other sites.
Avoid using too many scripts, and do not force html to handle server-side code (like php and shtml).
Avoid using https protocol as much as possible; encrypting and decrypting communications is noticeably more CPU-intensive than unencrypted communications.
Flash, video, audio, and image files are downloaded to the browser. This uses bandwidth only.
CLOUD HOSTING:
We use the CloudLinux operating system on all our servers, which is based on the Linux CentOS flavor. CloudLinux provides an extremely reliable backbone for shared hosting customers in the sense that it very effectively throttles sites that consume a peak in resources (a bad script, for example), so that the one website does not bring down all the others. Once the CPU usage on the peaking website subsides, throttling is decreased and the website is able to function properly again. The advantages to this are that the account is not suspended like it would be on shared hosting - the speed for that one site simply decreases. This way, the website that experienced the peak will not suffer any downtime as a result.
VPS and DEDICATED SERVERS:
You are allowed to use 100% of the CPU resources.
A good trick is to turn off the webstat programs (AWstat) that comes with your cPanel. Note that AWstat and other tracking tools use CPU and MySQL connections. By turning this off, you reduce your usage.