The Intel® D975XBX is the first motherboard used by enthusiasts to really push processors based on on Intel® Core™ better known as Conroe or Core 2 Duo or C2D and C2 for the extreme variant of Intel® Core™. It is the best, the cream of the crop, best of the best, baddest motherboard in town during the early pre-release days of Conroe and second to none. This motherboard is not for everyone looking for value, this is geared towards the top end, only for those who have the courage and money to spend.
Source:Article: Intel® D975XBX EPP [Extreme Processor Profile]? (Uber Motherboard for Intel® Core™-based Processor)