"The X4 will be our quad-core generation," Bretzmann said. IBM's chipset is used in four-processor systems that stand alone or that can be cabled together into larger multiprocessor configurations.
The X4 is, of course, the next iteration after their X3 chipset, which already supports 32 processors. IBM isn't mentioning plans for newer Opteron chipsets, but it wouldn't be surprising. Even though IBM has heavy investments in areas other than x86 processors, they still maintain that x86 is the majority of the market and are catering to that.