The Unix server market continues to contract as x86-based systems gain more capabilities, but the Unix category still US$2.3 billion in revenue last quarter, or about one-fifth of the overall server market, according to IDC. And if there's money to be made, vendors will keep investing, at least for the time being.

IBM's new, eight-core Power7+, expected before the end of the year, is being manufactured on a 32-nanometer process, compared with 45 nanometers for the Power7. The more advanced process enables smaller transistors, which means IBM could fit several new features on the chip while keeping it about the same size.

IBM used some of the extra space to expand the Level 3 cache memory to 80MB, from 32MB on the Power7. "This memory increase will lead to a major performance growth path for scale-up enterprise workloads," IBM's Scott Taylor said in a presentation at Hot Chips.

He also highlighted IBM's use of a memory type called embedded DRAM, which uses fewer transistors per bit compared with SRAM. The Power7+ has 2.1 billion transistors altogether, and it would have had 5.4 billion if IBM had used SRAM, Taylor said.

In that sense, eDRAM gives IBM the equivalent of a more advanced manufacturing process, so effectively it can put more functions on the chip that would otherwise require it to move to a new process, Taylor said.