604E MANAGES AROUND 225 SPECINT92 AT 166MHZ, ITS SMALLER AND COOLER

(October 24th 1995) The '604+' that we referred to in the last issue
was formally unveiled as the 604e at the Microprocessor Forum.
Previously there had been a bit of confusion as to the clock-speed
that the processor would be running at to achieve the estimated 225
SPECint92 figures. And the answer is 166MHz. IBM and Motorola are
phasing out SPEC92 speed measurements, so formally, the chip is now
being estimated to be capable of between 5.0 and 6.0 SPECint95. We'll
have more in the next issue on the new SPEC95 measurements.

Alongside a double-size L1 cache the 604e includes improved bus
ratios, the vanilla 604 allows designers to run the chip at up to 3
times the bus speed, while the 604e can support a 5:1 ratio,
important since the chip is designed to work a up to 200MHz. The move
to the more compact silicon design drops the size of the processor to
148mm square, whereas its predecessor (with a smaller cache) measured
196mm. The other consequence is that the 604e runs with a 2.5V supply
voltage compared to the 604's 3V.