I have a development machine with Apache installed as a service on Windows. The installation is fresh out of the box, with no changes to configuration aside from adding the PHP module.
From day one, I've had a problem that looks like this:
Essentially, Apache is freezing for about 11 seconds before replying on random requests. This appears to happen more frequently when the host hasn't been connected to in a while, but this is not always the case.
I've eliminated MySQL, PHP, and the specific application; this long wait problem will occur even when loading a static file such as favicon.ico. Thus, the only factor remaining is Apache, which is freezing for consistently around 10-11 seconds before replying.
The problem is not the DNS problem that many people point to; as you can see, the DNS lookup is instant, and the problem occurs both on localhost and 127.0.0.1.
Thanks for the time.