David Wilkinson wrote:
> Maybe it was technically necessary in order to move forward, but this
> need for hardware virtualization for Windows XP mode (and VPC 7) is
> going to cause a lot of trouble.
> See Ed Bott's blog at
> We are not just talking about old hardware here.
> Part of the problem is that hardware virtualization is not a well-known
> feature. Indeed I bought a 64-bit dual core machine 3 years ago (before
> I got into virtualization) and I never gave it any thought. So of course
> my machine does not have it (Athlon64 X2 on socket 939), though I know
> there were chipsets available at that time that did support it.
And back then, the pre-announcements of hardware virtualization made by
AMD and Intel looked like the feature would become available as a
CPU stepping or microcode update for existing CPU designs, ready to
be plugged into existing socket 939 and Xeon based computers.
But both AMD and Intel have decided to break backward compatibility with
motherboards/computers whenever they make even the smallest CPU
improvements. So users cannot simply buy a processor upgrade and pop it
into their existing computer, they have to replace a lot of non-outdated
hardware (sometimes the whole machine), just to get about 5 extra CPU
instructions and a few extra control registers.
It was much nicer during the transitions from 286 to 386, from 386 to
486, and from 486 to Pentium. In each case the chipmakers offered
"upgrade" or "overdrive" processors which had the latest hardware inside
but would fit in the old sockets on the old motherboards. (386SX was a
386 that would fit in a 286 motherboard design, there were
daughterboards for putting a 486DX in a 386 motherboard,
486DX2-OverDrive and 486DX4-OverDrive would fit in most 486DX boards and
there were a few Pentium 1 generation chips that would fit in a 486
Jakob Bøhm, M.Sc.Eng. * jb@xxxxxx * direct tel:+45-45-90-25-33
Netop Solutions A/S * Bregnerodvej 127 * DK-3460 Birkerod * DENMARK http://www.netop.com
* tel:+45-45-90-25-25 * fax:+45-45-90-25-26
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