Advanced Micro Devices Inc (AMD)

[sgolds]

chipguy, that misses the point -

The logic and microcode to implement all that legacy crap - from 16 bit code and segmentation semantics on up, is still there occupying space in the CPU core loading down the clock tree and leaking current from every last transistor.

It is partitioned separately and not even run under a 64-bit OS. It is not needed and can be jettisoned in a future version of the processor. Once 64-bit OSs are standard fare then why would anyone want it? You can run all your 32-bit and 64-bit applications totally without Legacy Mode.

K8 is a transition away from the old x86, it bridges both worlds. I do wonder what design restraints are in K8 from having to provide legacy mode, constraints which may dissapear from K9. For efficient use of die space, I imagine there must be circuitry which is common to Long Mode and Legacy Mode - that suggests an opportunity for further 64-bit optimization once Legacy Mode is tossed.