Comparing systems

Surely what matters when comparing systems is the performance for given required load, and the total cost i.e. hardware cost, software and support costs, energy consumption etc. Details like core count, amount of memory, disk etc. - who cares*? If system A performs twice as well as system B, it doesn't matter if it has 2x as much disk or half as much. Unless of course disk space is part of your performance criteria.

* ok I care, but I'm just interested, I'm not in purchasing :)