IBM’s forthcoming 45nm POWER7 server processor has 1.2 billion transistors and at 567mm2 (square millimeters).  What’s its secret? The first use of a special cache technology that IBM has been perfecting since 2007.

IBM’s POWER7 will come in 4-, 6-, and 8-core variants.  Each core features 4-way simultaneous multithreading.  This means it can handle up to 32 simultaneous threads per socket.  POWER7 is built for multisocket systems and it means that a full 32-socket system of 8-core would support 1024 threads.

The POWER7 has a pair of four-channel DDR3 controllers that can support up to 100GB/s of sustained memory bandwidth.  Supporting that is 32MB of on-die L3 (Level 3) cache.  They were able to put that much cache by using special embedded DRAM (eDRAM) which cuts the transistor cost roughly in half.

POWER7 can be compared with the power of Intel’s “Tukwila” Itanium processor with 8 cores and 30MB cache and 2billion transistors.  Definitely IBM did more with less.

Each core of the POWER7 is consist of a robust suite of execution resources.  There are total of 12 execution units:

• 2 integer units
• 2 load-store units
• 4 double-precision floating point units
• 1 branch unit
• 1 condition register unit
• 1 vector unit
• 1 decimal floating-point unit

That definitely is a one impressive microprocessor.  IBM definitely is still strong in the mainframe market.  Just imagine this processor powering your ordinary desktop computer? Sweet.