[ale] Emulator vs. Virtual Machine

[David Corbin]

Jeff Layton wrote:

> Hello,
>
>   Could someone help me with a 'discussion' I'm having.
> This other person is claiming that VMWare is an emulator
> and as a result is really slow. I'm claiming that VMWare
> is a Virtural machine and it's pretty darn quick. This other
> person also says there is little difference between emulators
> and virtual machine, at least as far as VMWare is concerned.
> Would someone like to jump to help me (or the other person)?
>
> Thanks!
>
> Jeff
>
> P.S. I've been using VMWare for about 4 years and found it
> to be very responsive, particularly on a dual CPU box.
>
A virtual machine uses the actual CPU to process the instructions for 
the code running in the virutal machine.   An emulator interprets the 
instructions much like the processor has to, but it implictly does it at 
"software speeds", not hardware speeds.  VMWare is both an emulator and 
virtual machine.  It emulates hardware, but all the Intel instruction 
set is processed by your actual Intel (compatible) CPU.

There's a reason you can't get VMware for Linux to run on non I586 
boxes.  It uses the Pentium virtual machine capabiliity.

David