Intel Pentium 4 2.8 GHz

A regular production Pentium 4 2.8GHz with an interesting twist: it runs on a 100MHz (QDR400) FSB! Most 2.8 GHz parts use a 200MHz (QDR800) FSB and the 'old' high-end use the 133MHz (QDR533) FSB. For a 2.8 GHz part it makes sense to use a 133MHz bus or higher to avoid creating bottlenecks. Intel also released a 3 GHz part with a 100MHz (QDR400) bus but I've never seen one; high clocked models on such a slow bus are quite rare.

For Office work the slow bus usually doesn't matter so much. High-end creation/gaming is a different story because those tasks rely on a fast bus and fast memory access.

Also, this CPU allows an extended upgrade path for those who want to stretch their previous S423 system. Using a PowerLeap S423 to S478 adapter you can instantly upgrade to 2.8 GHz whereas 'true' S423 CPU's only went up to 2 GHz.