JC,
Have you forgotten that 64-bit code is not the only difference that x86-64 adds? What about the extra registers, for example?
I understand that, but there are devices where performance is important, others, where it is not. For example drivers for printers, modems, keyboard, mouse, joystick etc. don't really justify rewriting to 64 bit code, at least initially.
Hard disks, video, network are some off the top of my head that would benefit from increased performance of 64bit code, and also, if there is some overhead involved when switching away from 64bit long mode to 32bit mode, it would be good to avoid this, from performance stand point, for these devices.
Joe |
