AMD's Dual Core Athlon 64 X2 Strikes Hard[/i]
If your applications benefit from dual core processors - see our benchmarks -
the Athlon 64 X2 is superior to the Pentium D 840 in a vast majority of our benchmarks. In addition, it is not any slower than its single core counterpart Athlon 64 4000+. Please note that we used a processor based on the old Clawhammer core, which explains the performance handicap when compared to the X2. The latest San Diego core will perform exactly as the X2.
When looking at the Intel lineup, the dual core Pentium D stops at 3.2 GHz, with the single core chips going all the way up to 3.8 GHz (Pentium 4 570). As a result, the Intel dual core chips will be somewhat slower under single-threaded environments if you consider replacing your system at an early point.
...the Pentium D system manages to burn over 200 watts as soon as it's turned on, even when it isn't doing anything. It even exceeds 310 W when working and 350+ W with the graphics card employed! AMD proves that this is not necessary at all: a range of 125 to 190 Watts is much more acceptable (235 counting the graphics card). And that is without Cool & Quiet even enabled.
Here's the bottom line. If we had to recommend a single core processor, the choice would depend greatly on the type of applications in use. But in the dual core arena, though, there is not much that speaks for Intel: go with the Athlon 64 X2.