🚀 go-pugleaf

Jack Mason wrote:

> If so, I am missing the distinction between dual core and SMP since
> it used to be that dual core was just a special case of multiple
> processors accessing the same memory.  We have had SMP around since

It still is. The difference in licensing cost is arbitrary.

> the early 1960's, the only difference being today we can cram
> multiple processors on a single chip as opposed to on a single board
> or in a single backplane.
> 
> The systems we have will all be single user, with the processors
> (hopefully not the operating system) determining how many processors
> need to be invoked and when.  So, hopefully, we would only have to

The processors cannot decide how many processors to use because the
processors have no knowlege of instruction order and the instructions
within a thread must be executed sequentially.

> license each system.  However, we don't want to have to relicense
> them each year as upgrades come out.

Database servers typically ship a new major version every three years
and you only need to relicense on a major version change.

> 
> What I don't understand is how Intel/AMD can build a PC board that
> has more processors, but runs an application 20 to 30 times slower
> than a single processor board.  Multiprocessors used to have a
> counter that detected instruction aborts and if a threshold was
> exceeded, that thread quit being multiprocessed.  Oh, well...
> Microsoft has never written a decent scheduler for Windows products,
> why should Intel have to learn how to correctly build processors....



-- 
Bill Todd (TeamB)