Chris Fellows wrote:
1. 2 4 quad core machines with your choice on RAM and number of drives 2. 10 (or more) commodity machines (as defined on the hadoop wiki)
I'm not sure what definition you're referring to. Quad-core processors are a commodity today, aren't they? So I think your question is perhaps where on the spectrum of commodity hardware is it preferable to be, on the high- or low-end?
Hadoop benefits greatly from ECC memory, which is not low-end. Multi-core boxes tend to give you more computation per dollar, per watt and per unit of operational maintenance. But the highest clockrate processors tend to not be cost-effective, as do the very largest drives. So I'd hazard that moderately high-end commodity hardware is the most cost-effective for Hadoop today. YMMV.
Doug
