If I had to guess, their secret sauce is that 1) they're paying lots of money to be on a chip fabrication node ahead of both AMD and Intel, 2) since their chip design is in-house, they don't have to pay the fat profit margin Intel and AMD want for their high-end processors and can therefore include what is effectively a more expensive processor in their systems for the same price, and 3) their engineering team is as good as AMD/Intel. Note that the first two have more to do with economics rather than engineering.