[darkhelmet]

You are correct. In spite of the carve-up of the company, many designers ended up at AMD. I'm a bit fuzzy on the details and it is second hand information, but as I remember it:

* The Alpha bus architecture was used directly as the foundation of the Opteron and Athlon64 chips.

* The Alpha chipsets were used for Opteron/Athlon64 (eg: irongate family)

* A lot of the internals formed the foundation of Athlon64/Opteron, including the floating point system.

* A bunch more foundational work that I wasn't clear on was used. Alpha was far more closely related to Athlon64/Opteron than a lot of people realized.

I did the FreeBSD port to AMD64 and had a bunch of back-channel contacts with former co-workers who moved to AMD at the time. I had a steady stream of engineering samples, toys, documents and gossip. I still have a bunch of it around somewhere as souvenirs.

Aside: My favorite "secret" was REX32 mode. It was a special mode where the CPU allowed access to the 64 bit registers in a 32 bit OS, think 32 bit WindowsXP. It did not require the OS to be aware of this. Context switching of this extra state was bolted onto the side of fxsave/fxrstor in reserved areas at the time. This mostly intended to allow things like hot spots of nvidia drivers and libraries to secretly work in 64 bit mode on Windows XP. I was told that it made significant improvements to benchmarks. Officially it was just an engineering test feature. Sadly, it was removed - for a number of reasons.