Pricing is probably the issue here or maybe not "At an expected $241, the Pentium D 820 is a bit more expensive than a Pentium 4 at 3.2 GHz. One should be able to cope with the performance impact caused by the slower clock speed since the improvement in multitasking and when using thread-optimized software is tremendous." from tomshardware.
It depends on which one you use, consumer or pro products.
The thing what most of you...