Low-power server processors compared

In previous server processor reviews, we've always covered the mainstream processor SKUs. Today, we're going to take a look at the low voltage parts that both AMD and Intel offer. Intel uses the LV nomenclature for their low voltage parts, and AMD uses HE to designate their low voltage parts. Both Intel and AMD have been shipping low voltage parts for a few years now, but it hasn't been until recently that these parts have started to see some growth in the industry.

The first question you may ask yourself is, "What makes a low voltage part?" A standard Intel Xeon (Woodcrest) is rated at 80W TDP, and their low voltage parts are rated at 40W TDP. Most of AMD's Opterons operate at 85W TDP and their low voltage parts come in at 68W TDP. At first glance, it would appear that Intel servers should utilize less power than AMD, but that would be an incorrect assumption. Given the many components that make up a server (especially memory), and the difference in how each vendor handles their different power states, there is more to low voltage than meets the eye.