Errrr. I'll elaborate on these topics, as someone who works in one of those two company as a verification engineer.
As CPU goes, here's some background.
Until 2000s, Pentium-D and Core-series, it was about frequency and pipelines. (Single thread performance)
CPU functioned as pipelined modules, each performing different tasks.
* Someone who reviews instructions
* Someone who understands the instructions
* Someone who calculates based on these instructions (multiple of these)
* Someone who relays these results.
Since AMD/Intel used similar architecture, frequency determined the relative performance.
You'll see lot of old people arguing performance based on the "Frequency" due to this reason.
Because Higher Frequency = More 1s and 0s switching per second, it got way too hot.
So Israel team, decided to modify Pentium 3 Architecture and use multiples of them to boost performance.
Hence, the Core-series.
Of course by this time, programming has changed.
Era of single thread programming was changed to parallel programming (Threads, openMP, etc)
But due to the difficulty in programming in parallel (due to resource sharing, deadlocks, coherency) people kept using single threads or coarse-grain locking (unoptimized parallelism)
So people kept using Frequency as Metric.
But if something can run multiple threads, more works can be done.
There are many other things to consider. Those information can be found here:
Intel's Sandy Bridge Microarchitecture
AMD's Bulldozer Microarchitecture
Anyways...
So the current state of AMD Bulldozer:
The current philosophy is to take a step-back trying to compete with Intel, because it was not working.
In addition, manufacturing process of GlobalFoundries(AMD) is currently 12-18 months behind Intel foundry.
(this is huge)
It focuses on Server-centric approach and have chosen some trade-offs in that context, and gain higher performance per mm^2.
During this process, AMD took a huge step in designing CPUs. M-space, SoC methodology for modular CPU design, so innovations have been made, but not enough to compete.
The current AMD processors are faster in clock, but not in single thread performance nor in multi-threaded performance given similar # of cores (this is hard to measure now because AMD architecture uses shared resources between 2 functional units, which are termed as single and/or dual core per block).
tldr: Pentium 4 with 5GHz clocks are not faster than Core2 2.5GHz. and Intel is currently better for now.
Good resource for looking at some general performance.
AnandTech - Bench - CPU