Geek sneak peek at Pentium III
February 17, 1999, 3:20 p.m. PT

update As Intel prepares to brief the press and analysts on the Pentium III today, reviews of the chip can already be found on Web sites--and some are less than glowing.

These reviews, not for the uninitiated, are often couched in arcane chip-speak. Aficionados, for example, may be impressed by front and back shots of the processor board in a piece by Chamila Sumanasekera at Review Zone.

But what may not strike people's fancy is the new processor's uncanny similarity to the Pentium II, especially in performance benchmarks listed on another site.

Like its older sibling, the Pentium III communicates with the cache memory at half the speed of the processor. The cache memory on the high-end Xeon processor, on the other hand, "talks" to the cache at full speed, or the same as that of the processor, resulting in better performance.

Also, the sizes of the first and secondary caches are the same as the Pentium II: 32 and 512 kilobytes, respectively. Both caches are critical for boosting performance. Generally speaking, the more cache, the faster the chip.

Like the Pentium II, it uses a 100-MHz bus, about 50 percent faster than the 66-MHz speed used on the Celeron processor, the mobile Pentium II for notebook PCs, and the veteran Pentium MMX chip. But, again, no improvement over the Pentium II.

Clock speeds, at least initially, are not very different. The top-of-the-line Pentium II runs at 450 MHz, while the Pentium III will come out at this speed and at 500 and 550 MHz.

Prices are listed at Review Zone as $560 for the 450-MHz Pentium III and $780 for the 500-MHz version.

Other reviews are more critical about the similarities of the two processors of the Pentium II and III.

"We're starting to wonder if perhaps Intel has another problem on its hands. You have to understand that the core of the PII, the Celeron, and the PIII is more or less the same core as the original Pentium Pro," according to ARS Technica, another Web site that is offering a detailed technical preview of the Pentium III, including a number of different benchmarks.

"This processor core started out at 150 MHz, folks. It's a good design, but Intel may be reaching a point of diminishing returns on its sixth-generation [chip]."

Nevertheless, the Review Zone spells out important differences between the chips too. Under "new media instructions," also known as "Katmai" instructions, it lists as improvements MPEG encode [creation] and decode (playback), 3D graphics, advanced AC3 audio, complex imaging effects, and "realistic physics."

Applications, however, must be written to take advantage of these potentially powerful instructions.

One underrated difference, according to Sumanasekera, is that the Pentium III consumes less power then the Pentium II and only requires 1.8V.

But he cautions: "This is the real question about motherboard support. Because although many motherboard manufacturers will offer BIOS updates for their products to detect the Pentium III, you have to make sure your motherboard will also support a voltage of 1.8V. Otherwise, you'll be providing the Pentium III with more power than necessary, resulting in a slight increase in surface temperature," he said.