[CST-2] Comp. Sys. Modelling

[Tim Harris]

> > The first bound provided by giving all devices Dav, so the
> > max throughput is
> > 1/Dav = around 18.6 transactions/s
> >
> > The second provided by giving as many devices Dmax as
> > possible, so the max
> > throughput is 1/Dmax = 10 transactions/s
> 
> But that doesn't take into account N or K, which I think it needs to as
> you'll need to queue for other customers to finish with the device
> you're waiting for first - it's taken into account in the notes when it
> considers the optimistic/pessimistic cases like you said, so we get  X =
> N/(N+3) x 1/Dav or 1/Dmax.

That part of the question's asking what the maximum possible 
throughput is for those optimistic / pessimistic bounding systems,
so it's only necessary to look at what the bottleneck device would be
in those cases.

> There must be more to it than that, I can't believe that inverting two
> numbers is worth 7 marks...

Well, you do also need to derive what the bounding systems would
be in order to get the numbers to invert :-)

Cheers,

Tim