/. have an link to Boost Socket Performance on Linux (at IBM). It's a really good article. It explains how one can add a couple of extra configs to a network socket to increase performance. By default, network server applications actually can't shift that much data that quickly (I've found this in the past), but it's possible to crank up the TCP stack to work more efficiently (assuming your application needs it).
A little bird told me that IBM are looking to wholesale move to Linux (servers already done, just desktops to go). As a result, the amount of Linux skill inside IBM must be astronomical. It's good to see them sharing that information, as it'll help everyone in the long run (and hey, maybe the applications they're using already will benefit too).