Big Mac #3

[Jnadke]

Originally posted by JosephM
As anyone can tell you, the more processors you add, the less effency you have, so that system for $100 per GFlop is based more on effency and less processors. Plus, all the Macs are off the shelf models, not stripped down motherboard only computers.

As anyone can tell you, the number of processors doesn't decide efficiency. The distribution of the load and network latency does. Lesser factors are processor usage and design.

If the number of processors decided efficiency, then the NEC Earth Simulator (with 5,120 CPUs) wouldn't be at No 1. The NEC Earth Simulator can reach a peak efficiency of 87 percent. By comparison, the AMD cluster above is about 45 percent peak efficient (and if you read the article, you'd see that they are off-the-shelf components as well).

The Mac cluster I've heard is only around 50-60% efficient. Don't go "then that means it will get more powerful". On the contrary, without a complete overhaul of its design, it can only hope to gain marginal increases in efficiency (a few percent) through software upgrades.