updated 01:35 pm EDT, Wed August 25, 2010
IBM details 5.2GHz mainframe CPU
At the Hot Chips 2010 conference on Tuesday, IBM talked about its z196 CPU for Z-series mainframe computers. Claimed as the fastest processor in the world, has a clock speed of 5.2GHz and will ship in September, though its price is expected to be anywhere in the range of hundreds of thousands of dollars to over a million. The chip is one of the only CISC chips left in the category, supporting large programs that need more memory than RISC chips such as PowerPC and ARM embedded processors.
The z196 houses 1.4 billion transistors on 512 square mm chip fabricated on 45nm PD SOI technology. It otherwise has a 64KB Level 1 instruction cache, a 128K Level 1 data cache, a 1.5MB private L2 cache per core and a pair of co-processors for cryptographic work.
A four-node system uses 19.5Mbytes of SRAM in Level 1 private cache, 144MB for Level 2 private cache, 576MB of eDRAM for Level 3 cache, and 768MB of eDRAM in a rarely seen Level 4.
The z196 uses 1,079 different instructions, 75 of which can be used by millicode, with 219 executable by millicode. Another 24 instructions are conditionally executed by millicode. IBM uses millicode to refer to instructions internally executed by the processor, similar but a little bulkier than microcode used in other chips.