Shakin' It Up

The new CPU from IBM is sending tremors throughout the industry. The PowerPC 970, a derivative of the awesome Power4, was officially announced the week of 14 October 2002 and was presented at the Microprocessor Forum in San Jose.

While it is doubtful Apple will make a commitment to its use at this point in time, it's still a fairly good guess they will go with the processor when it finally starts coming off the assembly line in late 2003 or early 2004.

Insiders also claim Apple is already testing it with OS X.

The big differences between the 970, adapted from IBM's impressive Power 4, and the G3 used in today's iBooks are that the 970 includes a vector processing unit, a far deeper instruction pipeline, a far higher clock speed, a high bandwidth memory bus, and 64-bit registers.

Initial offerings will clock at either 1.6GHz or 1.8GHz. The superior design of the PowerPC family, coupled with the increased processing bandwidth, can make it several times faster than a comparable 32-bit AMD or Intel.

IBM is currently testing Linux on the processor, running both a 64-bit and a 32-bit version. Thanks to a 32-bit native mode, 32-bit applications can run without a hitch. Operating systems have to be tweaked a bit, but not much.

AltiVec Alive And Well

The PowerPC has always had a 64-bit instruction subset, but it's rarely been used. The PowerPC family has included rules governing 32-bit and 64-bit processing from the beginning.

Motorola's AltiVec feature is alive and well on the 970, where it is called the Single Instruction Multiple Data (SIMD) processing unit. The 970's SIMD unit uses the same 162 instructions found on the AltiVec, so applications optimised for the G4 will run correctly on the 970 without being rebuilt.

Most other features agreed on are present as well. The 970 is namely 'Book E' compatible, following the instruction set most recently agreed upon between Motorola and IBM.

To build the 970, IBM will use 0.13-micron copper and its Silicon on Insulator (SOI) technology which allows for more efficient transistor gate operations, which in turn lets the 970 run at higher frequencies while using less power, which in turn means less heat - very important for the next generation of laptops.

At 1.8GHz the 970 will consume 1.3 volts and dissipate 42 watts; at 1.2 GHz, it will consume 1.1 volts and dissipate only 19 watts.

Which is admirable, considering the 970 has 52 million transistors on chip, as opposed to 33 million for the G4. At 1.8GHz it is expected to outperform the Power4, generating 18 million RC5 keys a second, and producing a SPECint 2000 benchmark of 937.