First let me say that, with some hesitation, this book is worth the read. If you're looking for a easy to understand text on x86 and RISC computing, this is your book. But after reading it I was left with more criticism than accolades. So let's start with the good:
From top to bottom it describes the microarchitecture of every Intel processor from the Pentium to the Core 2 Duo and likewise with every PowerPC processor with the exception of the G6, (which was released around the same time as this book). Jon Stokes (the writer) uses easily identifiable analogies to describe otherwise incredibly complex systems. He has a sort of "down to earth" way about his writing and throws in a few cute jokes about Oprah and smoking cigarettes. Anyone with a cursory knowledge of computing can understand 90% of the text in this book. All you need is basic logic skills, math, and a halfway decent memory for what was written in the chapter before. If you're looking for a text on how the Core 2 Duo works and what differentiates it from the Pentium 4 (or any other previous microarchitecture), this is your book. Same goes for the PowerPC line of CPU's. There's also GREAT chapters on caching and x86-64.
Now the bad:
The biggest bone to pick is that he almost completely leaves AMD out of the book. The only mention AMD gets is in regards to x86-64. He sort of gives AMD "cred" for x86-64 and then moves on to how it works. This is unfortunate because AMD has made a lot meaningful contributions to x86 computing; the most notable being the IMC on the Opteron. The IMC gets one sentence in the entire book, which is this: it exists. To expand upon this particular bone, he doesn't even mention Sun's SPARC or DEC's Alpha, both of which have had major influences on x86 and RISC. I was flat out floored that the IMC received so little mention in the caching chapter of the book.
Granted, AMD and Intel's x86 processors aren't radically different from one another (especially compared to PowerPC), but with the level of detail this book goes into, he could have at least dedicated a single chapter to the Opteron. Furthermore, it seems like he compares Intel processors to PowerPC/Gx processors just for comparisons sake. Now that PowerPC is essentially dead, why write half the book about it? Let's get real here, PowerPC isn't going to contribute anything meaningful to computing from here on out. It'll live on in supercomputing and very high end servers, but the aim of this book is desktop computing. Another major microarch that goes unexplored is Itanium. Yes, Itanium hasn't been a commercial success, but it's definitely the best performing 64 bit solution out there and it's a complete and total departure from x86 which makes it interesting in my book. (Yes, I do realize I just contradicted myself w/ the G6 and Itanium lines)
Moving on there's little mention of dual core computing or parallelism outside C2D. He puts a small paragraph in on virtualization, but doesn't explain what the benefits are. He also completely leaves out hyperthreading (which will reappearing in Penryn). He doesn't really explain the difference in manufacturing technologies or other parts of a computer's "system." You get the idea (in the VERY last paragraph) that the industry is moving towards parallelism and multicore computing, but he never explains why or what the benefits are. And my final complaint is that the book ends rather abruptly. There's no closing chapter or conclusion... just a small paragraph that says something to the effect of "intel is moving away from higher clock speeds and focusing on more cores and it's a really big deal." And BAM! it's over.
To sum it up, I was a little disappointed with the lack of AMD's mention and overall Jon doesn't really exude "excitement" about computing. He seems to forget he's writing a book and not a white paper. Still, the book is probably one of the more definitive publishings on Intel's modern day x86 CPU's and IBM/Motorola's PPC line of CPU's, all written in a way easily understood. I wouldn't say it was a complete waste of my time, but a newcomer to computing would walk away from this book with almost no knowledge on Intel's biggest (and most important) competitor: AMD. Jon makes out Intel's biggest competitor to be IBM and the PowerPC line of processors, which of course is absurd.
I hate to call this book biased, but it's hard not to after reading it.