Manuel Lemos - 2007-05-31 03:20:10 - In reply to message 1 from Abraham L.
I cannot tell much by experience because I did yet need to handle loads that cannot be dealt by a single server, thanks to all the measures that I mentioned.
I am sure some day I will hit the limit with this site or maybe some other site that requires more resources.
From what I heard, some very busy PHP sites are using pools of servers with PHP running with FastCGI and memcached to share cached information without loosing performance.
If you do not own your data center nor have access to affordable co-location services, maybe those services that your mentioned or even Amazon EC2 (Elastic Computing Cloud) can be affordable alternatives.