When AMD's "Barcelona" Opterons made their debut last Monday, we couldn't tell you about a sleek, black box nestled in among the other test systems in Damage Labs. Housed inside of it: an example of Intel's brand-new "Stoakley" dual-processor platform, complete with a pair of Xeons based on 45nm process technology. These Xeons are the first members of the Penryn family of 45nm CPUs to reach our test labs, and they offer a tantalizing look at how Intel will counter AMD's new CPU design with a substantially revised version of its own potent Core microarchitecture.

These new CPUs and the platform that supports them promise marked improvements in performance, thanks to a bevy of tweaks and updates. In fact, although the new Xeons are more a minor refresh than a major overhaul, the gains they've attained are formidable. Today, we can show you how these processors perform.

The contest between next-generation CPU architectures has begun in earnest. Read on to see how Intel's 45nm Xeons match up with AMD's quad-core Opterons.