Bluehost和很多大型美国主机商一样，提供的是不限空间、不限流量的方案，其性能和口碑是很好的。和其他虚拟主机一样，Bluehost主机也有诸如cpu、最大文件数等限制。
Cloud查过Bluehost、以及和Bluehost同一家的Hostmonster的TOS，其文件数限制都是20万，mysql连接数是20，而cpu限制并没列出。
向Hostmonster咨询，得到如下答复：
We will throttle the hosting account once you reach 7%.
Throttling is a method of easing the load on the CPU, to prevent one account from interfering with another’s performance. If your site is experiencing throttling it simply means that you came close to causing slowness for other accounts on the server.
CPU Throttling will not always cause slowness on an account and occasionally makes a site run faster. It’s also good to note that a few seconds of throttling every hour is not extreme and likely not an indication of a problem.
For more details, see the CEO’s blog at http://www.mattheaton.com/?p=208.
即Hostmonster的cpu限制是7%。Cloud又Google了一下，发现Bluehost和HM相同，也是7%（Bluehost另有高端的Pro方案，cpu限制是12%）。
Bluehost/Hostmonster的cpu限制看上去不高，实际负载还是很好的。