Well, given that the 83xx series only uses 75W, while the Intel quad-cores use 120W, An equivalent machine (63 Barcelona noes vs. 126 Intel nodes) should run a LOT cooler.
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It's close to a nightmare to try to review a server CPU in a few days, but we hope we have at least provided you with an idea what AMD's newest quad-core is capable of.
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and
Considering that AMD prices this Opteron 2350 under the Xeon 5345, AMD has an attractive price/performance offering for most applications. The only exception is a chess engine and highly optimized Intel binaries. Although our testing is not finished yet, there is very little doubt that AMD's newest chip is very energy efficient. Add to that the fact that the AMD platform is not burdened with the extra power consumption of FB-DIMMs, and it is clear that the third generation of Opterons will lead in the performance/watt area for a few months.