Worthwhile CPU Alternatives

by Alan Zisman (c) 1998. First published in Canadian Computer Wholesaler, July 1998

Last month, we looked at Intel?s new Celeron processor (originally code-named Covington), a dumbed-down version of the Pentium-II, aimed at the low-cost market.

We were less than impressed, since by leaving out the Pentium-II?s L2 cache, the 266 MHz Celeron?s performance suffers, in some cases testing out even slower than last generation?s plain Pentium. Because Celeron uses the Slot 1 design as a real P-II, it seems to aiming to get manufacturers to drop support for the Pentium-era Socket 7 design, dropping capability with Intel?s competitors at the same time.

Intel?s new offerings for high and mid-range machines were more impressive. These fit in with the company?s new strategy of having separate product lines for high, medium, and low-end systems rather than simply selling older and older models for lower and lower prices.

At the top, look for yet another made-up name: Xeon. While it sounds like a cartoon Amazon warrior, Xeon is a processor aiming at the growing network server market. Like the Pentium-II (and Celeron), it ships in a cartridge, but unlike the other two product lines, it doesn?t fit into a Slot-1 standard motherboard. Instead, Xeon requires a new, oversized Slot-2 design. These new motherboards will all run at 100 MHz, speeding up the whole system. As well, unlike the P-IIs, Xeon is optimized for multi-processor designs. Expect to see server models with up to eight processors, compared to a maximum of two for P-II designs.

In addition, Xeon processors, running at 400 and 450 MHz, include a beefier L2 cache than standard P-IIs, as much as 2 megs, and allows the processor to access the cache at full speed, rather than half-speed as with the P-II design. All these changes result in a much more powerful system, but count on Intel to price Xeon accordingly (over $2,000US each in bulk).

While the server market is growing, these high-end machines represent a small (though profitable) market segment. The bulk of the market is split between low-end and mid-range computers. Intel also upped the ante for the mid-range, with its ramped up Pentium-IIs. While the speed increase, to 350 and 400 MHz, may seem only a modest improvement over the previous 333 MHz speed champs, this was accompanied with a new motherboard chipset, the 440BX, allowing motherboards to run at 100 MHz, up from 66 MHz.

Speeding up the motherboard increases the speed at which the CPU can communicate with RAM, and could result in noticeable performance increases. There are, inevitably, a couple of things to note, however.

? Despite the promise that the speedier system bus, combined with faster processor will speed up overall system performance, initial testing results are less-impressive. When 350 and 400 MHz CPUs on systems with 100 MHz-bus were tested against 33 MHz CPUs on 66 MHz systems, the newer faster systems offered only relatively modest improvements when running standard business productivity software. The faster systems shone compared to the older models when run as network servers, however, especially as the number of clients accessing the network increased.

? The newer 100 MHz buses require faster memory than the older systems. And currently, these faster SDRAM strips are considerably more expensive than the more standard units. Installing 66 MHz SDRAM onto a faster machine will not only slow the system down, but it may produce random (and hard to diagnose) system errors and halts. At worst, it can prevent a system from booting. The moral?make sure your fast system includes memory designed for it. If you want the fastest system, you?re going to have to be prepared to pay for it.

Intel?s competition, however, are not simply sitting back any longer and letting Intel define the marketplace. In the past, this competition tended to limit themselves to releasing lower-priced clones of Intel?s last generation. Now, however, they are starting to take the initiative on several fronts.

The three alternatives, Advanced Micro Designs (AMD), Centaur (Integrated Design Technologies), and Cyrix have united to, for the first time, propose a set of new processor commands. The 3D-Now instruction set aim to enhance graphic and multimedia performance, if programmers write code that make uses of the new instructions. 3D-Now will be supported by Microsoft?s upcoming Direct-X 6.0, due later this summer, but will not be compatible with Intel?s MMX-2. But with MMX-2 not due until next year, the non-Intel companies are hoping for a window of opportunity to become an established, and supported alternative standard.

The first released product featuring 3D-Now is AMD?s 333 and 350 MHz K6-2 processors. While continuing to utilize the Pentium-style Socket 7, these CPUs will be able to run in motherboards with 100 MHz system buses, allowing systems to be designed offering high-end P-II performance at a lower price. The original K6 processor was well-received?expect to see a wide range of K6-2 models, if the company can successfully overcome production problems that limited output throughout 1997.

While we?re on the subject of competition to Intel, it may be worthwhile to step back from the PC-environment entirely, and take a look at the PowerPC.

You?ve probably seen the TV ads where Apple suggests that the chips in its G3 Macs are ?up to twice as fast? as Intel Pentium IIs running at the same speed (though the image in some ads of a P-II strapped onto a snail suggests that they?d like us to replace the term ?running? with ?crawling?).

Apple is basing its claim on a series of tests done by Byte Magazine, using their ByteMarks benchmark tests. These tests do suggest that in integer operations, the G3 PowerPC does surpass the P-II. Floating point operations are also faster, though not by as wide a margin. But tests comparing real-world systems are less conclusive. MacAddict Magazine, for example, was surprised to report that on some Adobe Photoshop operations, the P-II machine out-tested its G3 Mac counterpart.

Despite this ambiguity, Apple?s products are an increasingly viable alternative to Intel-powered iron, and as they increasingly support PC-originated hardware standards, such as EIDE drives, PCI bus cards, and now Universal Serial Bus, the market for Mac add-on products is becoming more competitive, and potentially profitable.