The PS703 crams 16 Power7 cores into one blade, up from eight cores in the PS701. The PS704, which IBM calls a "doublewide" because it snaps two blades together with high-speed interconnects, will support up to 32 Power7 cores, up from 16 in the PS702 doublewide released last year.
IBM doubled the density by shrinking the packaging around the processor and using new, "ultra-small" memory controllers, it said.
"Based on the combination of these new technologies, the layout and configuration of the design allowed for placement of two 8-core P7 processors on a single wide blade, while still preserving 16 DIMM slots and support for new solid-state disks or rotating storage options," IBM said.
The Power 750 is getting a moderate speed bump from faster processors. The new options include eight-core Power7 chips running at 3.6GHz or 3.2GHz, a six-core Power7 at 3.7GHz, or a four-core Power7 at 3.7GHz.
The Watson supercomputer that won Jeopardy earlier this year was built from a cluster of Power 750 servers, along with IBM's DeepQA and other software.
Watson showed that a machine can outsmart humans under certain conditions, but IBM still has a niggling problem: who wants to buy one?
"At this point we don't have that many customers that want to buy a Jeopardy machine," Rosamilia acknowledged.
IBM has been trying to find commercial uses for other Watson-like systems and believes it has found one in the medical world.
Watson was good at sifting through massive amounts of unstructured data very quickly to find the best answers to a question. If a doctor could input a patient's symptoms, blood tests and other data, a computer might be able to sift through reams of medical histories and other data and suggest possible diagnoses, Rosamilia said.
"Think of this as a medical assistant, not a replacement for a doctor," he said. "The computer can say, Here's what I think the problem is and here's my degree of certainty about it."
The new 750 processors will be available May 20, and a system with a four-core processor starts at $30,180. The new blades will ship May 20, IBM said. Pricing for those wasn't available.