Here's another article...from cnn.com:
cnn.com
Review: Athlon will rock processor market
October 5, 1999
Web posted at: 11:47 a.m. EDT (1547 GMT)
by Rawn Shah
(IDG) -- I wouldn't normally write an article about a computer processor, but Advanced Micro Devices' recent achievement with the Athlon processor is too impressive to pass up.
The Athlon is interesting not only because it can compete effectively against the Pentium III class chips from Intel, but also because it runs faster, scales easier, and consumes less power. So if you're planning to buy any computers in the next quarter, hold off until you've looked at the Athlon-based systems.
Once calling it the K7, AMD followed the trend of using words, not numbers, and decided to rename its processor. For me Athlon conjures up images of a Greek restaurant chain -- "Hello, this is Athlon Pizza" -- but I imagine AMD hoped to differentiate the chip from its current product line and find a trademark that had the ring of high performance.
Busing around
The Athlon is the first generation of processors to replace the K6's Socket 7- and Super Socket 7-based interfaces. Its Slot A bus also happens to be the Alpha processor's EV6 bus, but you can't simply replace it with an Alpha processor and expect it to run. The chipsets are completely different, so you're at the mercy of OS vendors and motherboard manufacturers. MORE COMPUTING INTELLIGENCE
Slot A looks much like the Pentium II and III's Slot 1 interface but is incompatible with it. In fact, inserting an Athlon into a Slot 1 interface, which has a higher voltage, can cause irreversible electrical damage, so don't do it!
The change to the Slot A bus means you need a whole new machine for an Athlon-based system, but several brand-name vendors offer such systems already.
Slot A was designed to support the 64 bit Alpha processors, and it continues to be used as a bus for the Athlon. But that doesn't make the Athlon a 64 bit processor; to keep compatibility with the Pentium family and all supported software, the Athlon has to remain a 32 bit processor. Still, the bus allows for future growth without worry.
Intel, on the other hand, has a completely new interface -- currently labeled Slot M -- for its forthcoming 64 bit Merced processors. AMD thus has the advantage of not having to redesign its chip-and-motherboard interface for the next generation.
The Slot A bus runs at 200 MHz, twice the speed of most Pentium III machines, and promises to grow to 400 MHz. The system bus makes a huge difference in the performance of the machine because it defines the communication speed with and through the system chipset and components such as other processors, the physical memory, and the peripheral bus. Athlon will make the biggest difference in multiprocessor systems: most memory chips still run at 100 MHz, although 133 MHz SDRAM is just around the corner.
Intel hung on to the 100 MHz bus until recently, when it moved to 133 MHz with the new PC-133 SDRAM chips, expected to ship soon. The company had once planned to skip the 133 MHz memory route and go straight to Rambus DRAM (RDRAM), but the demand for RDRAM was then too low and the cost too high. Intel now plans to offer both RDRAM and PC-133 SDRAM memory systems.
AMD plans to stay with the PC-133 and Double Data Rate (DDR) SDRAM for its memory support of the Athlon. It's also putting out the AMD-750 chipset, which implements a memory controller, a PCI controller and bridge, and a uniprocessor interface. A different chipset will be announced for the Athlon's multiprocessor versions.
The AMD-750 chipset supports
The AGP 2x interface, which gives twice the common accelerated graphics port speed of most computers
PCI version 2.2, supporting up to six PCI slots
UltraDMA/66 IDE, 66 MHz IDE drive connections that can transfer data at 66.6 megabytes per second (MBps) in burst mode
Up to 768 MB RAM
A universal serial bus hub with four ports
Plug-and-play and advanced power management (APM 1.2) standards
Multiprocessing capabilities
Multiprocessing requires the Athlon to have a chipset that supports a symmetric multiprocessor (SMP) system for Windows NT. AMD is working on its own multiprocessor chipset, but with the licensing of the Slot A bus to other chipset vendors such as VIA Technologies, SiS, Trident, and Acer Laboratories, expect to see those vendors attempt to manufacture one as well. AMD plans for at least dual, quad, and eight-way SMP-supporting chipsets, although no release dates have been announced.
The Athlon was designed to run point-to-point connections in the multiprocessor configuration used by the Pentium IIIs, so a switch had to be placed within the chipset to allow the processors to communicate. Because a bus's bandwidth is shared by all its connections, the effective bandwidth of a quad-processor Pentium III system is 800 MBps divided by 4, or 200 MBps.
A switch, on the other hand, doesn't diminish the effective bandwidth available to the processor because each connection is separate from the other connections. Thus, the 3.2 gigabits per second (Gbps) bandwidth of the Athlon remains pure in a quad-processor system.
HotRail (formerly Poseidon Technology), based in San Jose, CA, is working on the chipset's core logic for a switched architecture that will support up to eight Athlon processors in a single SMP system. To prevent a memory access bottleneck, the chipset would have multiple memory interfaces to separate banks of memory. The core logic will be able to move up to 3.2 Gbps between processors, compared with Intel's long-overdue eight-way Profusion SMP chipset, which can do only 800 MBps. HotRail's product can also be adapted to other processors, including Intel's.
The chip
The Athlon implements all the instructions that the Pentium does, plus AMD's own 3DNow! instruction set. The additional instruction set is comparable to the Pentium III's SSE instructions that provide services for supporting multimedia.
The L1 (Level 1) cache on the Athlon is 128 KB, four times larger than that on the Pentium IIIs; Intel plans to move to a 128 KB L1 cache after its 600 MHz chips are released. The AMD has a 512 KB L2 cache, matching that of the Pentium IIIs, and while Intel's Xeons still have the larger L2 caches of up to 2 MB, future Athlons will hold up to 8 MB in an L2 cache.
At this time, only processors such as Sun's promised UltraSPARC III and IBM's Power3 chips can go that high, and those are intended for high-end workstations and servers.
But what can it do?
OK, so the Athlon has some dandy features. Can it do anything a Pentium III chip can't? Of course. First and foremost, it provides complete compatibility with the basic Pentium instruction set. (Some users still have the misconception that AMD's chips cause many incompatibility problems. Untrue!)
The Athlon and other AMD chips also differ from the Pentium III in their graphics instruction sets. AMD created 3DNow! to boost the performance of multimedia applications, 3D tools, games, and audio applications. When Intel finally caught up with its SSE instruction set in the Pentium III, it was too late to draw the interest of game developers, who'd already sided with AMD.
PC game software is now among the most demanding of applications; it has pushed the limits of high-end consumer hardware and brought growth to peripheral card vendors in graphics, audio, and input/output devices.
The Athlon may become the new favorite of PC hobbyists attempting to manually increase the chip speed -- for example, from 500 MHz to 700 MHz. The process, known as overclocking, yields the same performance as a 700 MHz chip. Although the procedure is complicated and best left to experts, its gains are appreciable.
Intel specifically warns that overclocking will void the warranty on its products, although AMD is more lenient and has even allowed some partners to do it. Kryotech, makers of cooling systems for processor chips, now has a full tower-size box that runs the Athlon at 800 MHz under full warranty from AMD. That, by far, outdistances the Pentium III.
As soon as multiprocessor motherboards are released for it, the Athlon will be best used in high-end PC workstations and servers. And it's expected to drive prices down. The price of the Pentium III Xeons -- $1,500 to $3,000 -- is set mostly from a marketing perspective. Even with large L2 caches of up to 2 MB, the manufacturing cost of the largest chip is still under $1,000.
And although AMD's current Athlon releases aren't quite up to the task, future versions will support equally large L2 caches, and larger ones will probably beat the Xeons in a performance contest. Intel hasn't had serious competition against the Xeons until now.
Currently, no major vendors have announced servers to run on the Athlon, but look for that to change as AMD releases the server version of its chip.
In reaction, Intel is cutting prices on existing chips to stay competitive with the Athlon and also plans to release a host of new chips in the next two months. If nothing else, we should all thank AMD for bringing real competition to the marketplace!
Compaq and IBM are already marketing Athlon-based systems. Compaq is releasing its new Presario computers with 600 MHz Athlons at $1,999 for a configuration with 128 MB RAM, a 13 GB drive, a 3Dfx graphics card, and a 17-inch monitor. Its slower 550 MHz Intel Pentium III is priced at $2,499.
IBM has released its Aptiva consumer series E and S, both of which use the Athlon chip. The S series models, which run the 600 MHz and 650 MHz Athlons with 128 MB RAM, a 20 GB drive, and a Nvidia card, are priced from $2,000 to $2,299. The E series models run the 500 MHz and 550 MHz Athlons with a smaller configuration and cost around $1,000.
Think of it this way: for $1,000 you can buy a system that would have been among the world's 500 fastest supercomputers five years ago.
The Athlon was released only a month ago, so it's not surprising there aren't many systems out yet. Expect more to arrive over Christmas and New Year's. Also expect the Athlon to be distributed among different (and renamed) product lines for the low-end consumer, high-end consumer, high-end workstation, and server markets.
I, for one, can't wait to get my hands on an Athlon-based workstation.
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