IBM holds the record for the highest clock-speed CPU. The quad-core z196 runs at an astonishing 5.2GHz, taking the title from IBM's own 4.7GHz Power6 CPU. The new chip contains 1.4 billion transistors - 300 million more than Intel's six-core desktop CPUs - on a 512mm2 package made using a 45nm manufacturing-process.
Each core has been given 1.5MB private L2 cache as well as access to 24MB shared L3 eDRAM cache. z196 also has access to a fourth layer of cache off-chip. Six of these CPUs can be installed into a multi-chip module (MCM) and will connect to each other through two controllers with total of 192MB shared L4 cache via 40GB per second link. Another relatively unusual feature is the use of CISC-based z/Architecture, as opposed to a more common RISC ISA.
According to presentation, z196 will find its way into IBM's Z-series mainframes and should start shipping at some point in September.