I have had a physical copy of this book for a few months now and love it. I recommended it in a presentation that I did for a SQL Saturday as a good resource for beginning and accidental DBAs to understand the physical needs of SQL Server and what effects changes to the hardware can have on performance. It also has a great section on benchmarking.
I had been away from the Windows world for seven years doing database development in a cross platform RDBMS named 4th Dimension and just about all of my work was done on Mac OS with the final solutions deployed on Mac and Windows. During that time I had lost track of changes in non-Mac related hardware. I did occasional work in SQL Server 2000 administration and design, but nothing where I had to deal with the hardware.
This book helped me get back on track with processors, chip sets and generally the changes in hardware.
(What color is your database?)