Let's look at the IBM 970


I was interesting in figuring out what the effect of Apple moving to an IBM 970 CPU would have on their product line. Although they are not shipping (expected 2Q-2H 2003), there is some information about them available in the market based on test samples and presentations that IBM has given.

This article will contain information gathered from a number of sources throughout the net.

From an article written in fall of 2002 after the chip conference that IBM used to show their new offerings, there is quite a bit of preliminary information. Further, IBM reveals in its press release quite a bit as well.

In summary, here are the chief points for the first released CPUs:

  • Based on IBMs high-end Power4 64-bit architecture
  • 64-bit operating core with 32-bit "native" mode for runing 32-bit executables
  • 42-bit addressing (that's 4096GB of addressable "RAM" or I/O space)
  • Altivec-compativle SIMD instruction set
  • 1.4-1.8GHz CPU core
  • 2 900MHz 32-bit one-way interconnect bus (basically an integer divisor of the CPU core) paths to the system support chip.
  • 6.4GBPS memory bandwidth
  • 512K on-chip L2 cache
  • 64K I / 32K D L1 cache
  • 13-micron CMOS process 8-level Cu
  • 42W power consumption at 1.8GHz (19W at 1.2GHz) Further speculation in the Real World Tech article centers around what Apple would do about the support chip, especially in dual-processor machines where the chip would have to arbitrate between the CPUs for access to resources, and the makeup of the memory subsystem, which they conject would have to be dual 2700DDR in order to keep up.

For additional information:

  • IBM's Product Presentation (PDF) By comparison, 800MHz FSB is expected to be available on Intel platforms (although it is still uncertain what the memory subsystem will be for that), and Intel is expecting to be pushing about 3.6GHz.

Based on today's numbers, a single 970 should match wits with a 2.4GHz P4 with 533MHz FSB. However, the question will be what the final tally is when the chip ships, and whether a dual-processor system is really viable in that timeframe.

Power consumption still looks very good with these chips (about 2/3 of a 2.4GHz P4), and is likely to make life easier for putting into multi-processor machines and possibly even laptops.