IBM sets world clock-speed record

Biggish Blue boffins at the Hot Chips conference showed off what IBM claims was the world’s fastest CPU clock-speed.

IBM managed to get a quad-core z196 running at 5.2GHz. Currently the world’s clock-speed record was held by IBM with a 4.7GHz speed hit by the Power6 CPU.

The latest chip has 1.4 billion transistors on a 512mm2 board built using the 45nm manufacturing-process. The old Power6 CPUs had only 1.1 billion transistors.

IBM was telling the world+dog that each core had been given 1.5MB private L2 cache as well as access to 24MB shared L3 eDRAM cache.

The z196 had access to a fourth layer of cache off-chip. IBM said that six of these CPUs can be installed into a multi-chip module (MCM) and connected to each other through two controllers with a total of 192MB shared L4 cache via a 40GB per second link.

The extra memory is needed to make sure the data runs smoothly because the processors are so fast.

They also use a CISC-based z/Architecture which is not much like the more common RISC ISA.

Biggish Blue has a cunning plan to stick the z196 under the bonnet of its Z-series mainframes which should begin shipping next month. So this probably means that you will never get to try out a shoot-em-up on the beast. 

Hexus pointed out that the Chip has been announced since July, but this is the first time that Biggish Blue has provided any details about its clock-speed, or shown what it can do.