the book is a great reference guide for pci-x
(a relatively new standard).
everything about this computer architecture is explained in details.the only limit is the purpose of this book, that remain in the bounds of a reference guide and not a programming & architecture guide.
the differences between pci and pci-x are clearly explained.
if you don't know anything about standard pci architecture and assembly programming,this book is not for you; but
if you are a system designer interested in pci-x, this book is a must.