David Christensen wrote:
dual network interfaces, and dual power supplies come to mind. I am
unclear about dual processors and/or dual memory banks.
There are no systems that I'm aware of which allow you to use 2
or more processors of different models; they always have to be
exact duplicates. Sometimes different step revisions of the same
model will not work -- if Intel makes a Xeon 5254 in March, and
fixes things in June, August and November, sometimes the
November release won't work perfectly with a chip produced in
March.
You can always use identically spec'd RAM from different
manufacturers in different memory banks, but since it's always
possible to power down, replace or just remove memory, and power
up again, I don't know that there's any reason to bother
distributing the manufacturers in a single machine.