We rely on the motherboard and system manufacturers to maintain such compatibility information because their testing requires the use of our processors (not vice-versa). The board must be validated for the power and thermal specifications of the processor. The manufacturer must release a BIOS update for the board with explicit support for the stepping and frequency of the processor. They should also provide any configuration changes or updates specific to the board. Compatibility and upgrade information must be specific to a motherboard, and it must come from the motherboard manufacturer.
We recommend contacting the motherboard manufacturer for compatibility information between the Intel(R) processors and the motherboard in question.
Specifications on the Intel® Pentium® D processor 820 can be found at: http://ark.intel.com/products/27512/Intel-Pentium-D-Processor-820-(2M-Cache-2_80-GHz-800-MHz-FSB)