PHP bottleneck

[Anon]

Some people say that PHP bottleneck is processor or network. Does anyone know the tools used to measure it? I use Linux. And how do I know which one is my problem between those two...?

[toma42]

use the command
top
to see what's taking up resources. Generally people make the mistake of running the database server on the web server and the database slows it all down.

[Anon]

If you're on a 64k leased line, it's quite likely that a Pentium 100 can deliver dynamic PDFs and graphics via PHP/libgd/libpdf faster than 64kb/s. If you're on a big fat pipe of say 1000Mb/s, it's likely that even a quad Xeon can't flood that pipe generating dynamic content like graphics and pdfs and such.

Usually, the limit for most servers is their bandwidth if the bandwidth is small (say under 100kb/s) and CPU if you have high bandwidth available.