Other vendors aren't like Apple and want all the business they can get. Apple's 12-core box will probably be more than dual CPU 12 core boxes that will likely have faster clock-rates, offer 4 times the memory support and 4 full PCI-E x16 slots. Hardly efficient for users.
Apple's box will probably cost less for a wide spectrum of those competitive configurations.
a. Apple will only have one bank of RAM to fill. That is actually an advantage is trying to hit a lower price point for standard configurations.
4 x 2GB RAM DIMMs is going to be cheaper than 8 x 2GB RAM DIMMs. More RAM in the second but also paid more.
b. Apple's one 12 core is going to cost less than two of the 'old' top end 6-8 cores. If up against two 'old' entry-mid level 6 cores offerings then probably will have base clock speed advantage.
Apple's out-the-door with a standard configuration price is likely going to be lower than some z820 or T7600 model . That extra "potential" value of 4 x16 slots and substantially more RAM DIMMs slots are going rack up a price premium with the other major system vendors in price.
The Mac Pro will do somewhat less and cost less ( Especially if Apple wrangled a deal for their custom GPUs cards and uses that for cost competitiveness. )
There is nothing in the new design that indicates Apple is trying to compose a system that costs much more than dual package , everything and the kitchen sink inside , workstations. In fact, it looks to be very much to be geared to undercut those prices.
The Mac Pro is aimed far more at replacing the current
single package Mac Pros. There is some targeting of old dual customers were the second GPU can take over computational duties, but buy-in-large it is a CPU users that are targeted. The design is going to rely on Intel steadily cranking up the 2600 core count to enhance that "partial coverage" over time.
