Advanced Micro Devices Inc (AMD)

[HailMary]

You are partially correct. A 64 bit OS is necessary for running 64 bit apps for many reasons (o/s needs to know memory mapping, registers for state saving, switching processor modes, etc.). And 64 bit drivers and libraries will be necessary for these 64 bit apps as well.

All the 32 bit apps, however, will continue to use the legacy 32 bit drivers.

A 32/64 hybrid OS is going to have 2 sets of drivers and libraries - legacy 32 bit and the new 64 bit.

So MSFT could release a 64 bit o/s today with limited 64 bit drivers and libraries (essentially what the beta is now), and it would run all existing 32 bit apps with the current 32 bit drivers. The problem comes in with the new 64 bit apps not having all the needed 64 drivers and libraries ported. They can't use the 32 bit drivers and libraries.

edit - looks like I'm wrong about the drivers as I posted 2 messages down

HailMary