AMD's Athlon CPU: A New Era?
by Alan Zisman
(c) 1999. First
published in Canadian Computer Wholesaler, August 1999
In the quest for the most powerful, the gold medal has
held by Wintel standard-bearer Intel?s processors. (At least if we talk
about PCs? I know all about PowerPCs, Mac-fans, you don?t need to
Intel?s competitors, AMD, Cyrix, Centaur, and the rest
have tended to
be the bottom-feeders of the computing world?producing processors aimed
at the low-cost, low-profit end of the market, while leaving the
cutting edge, along with its cutting-edge profits to Intel. The
often produced faster versions of CPUs than Intel ever did?but only
Intel had moved on to a newer product line.
Those days may have ended with the June release of
AMD?s K-7 processor?now
being marketed under the name Athlon.
Personally, I don?t like the name, and feel like it
loses some of the
momentum the company has built behind its respectable K6 and K6-2
lines. But there?s no doubting the processor?s speed and power?whatever
its name, with versions running at up to 600 MHz (along with lower-cost
500 and 550 MHz versions), the Athlon/K-7 speeds right past Intel?s
Of course, megahertz alone doesn?t mean much (as
Macintosh PowerPC fans
will point out). You can?t simply compare two processors by clock speed
alone. AMD?s new design includes many advanced features.
There?s 128 kb of high-speed cache built right onto
the CPU itself.
With this as Level-1 cache, the cache within the cartridge becomes the
L2 cache, while cache-RAM on the motherboard becomes L3 cache. By being
built right onto the CPU, the L1 cache offers very fast access, with
to the L2 and L3 cache-RAM as needed.
The Athlon marks the first time that any of Intel?s
left behind a Pentium-style design. The processor ships in a Pentium-II
style cartridge that is, in fact, mechanically identical to that Intel
model. The keyword here is ?mechanically??while the Athlon cartridge
fit into the Slot One on a motherboard designed for an Intel cartridge,
it won?t actually work there. Instead, it requires an electrically
design, built especially for the Athlon, using the EV6 bus protocol
designed for the Alpha CPU.
And that?s both good news and bad news.
The new design allows motherboards built for the
Athlon to run at 200
MHz?far in excess of the 133 MHz speed of Intel?s top products. The EV6
also supports scalable multiprocessing, for high-end designs with
processors?a market that has been, until now, owned by Intel. But it
means that manufacturers have to be committed to using the AMD
can?t just plug it into an existing system board design. We?ll have to
wait to see about availability.
The Athlon is being built by AMD using 0.25 micron
technology at their
Austin, Texas fabrication plant. The company has been hurt by
problems in the past, making it difficult to produce all the CPUs they
could sell?they seem to now have the system under control for the K-6
lines, and hopefully will not be plagued with the same sorts of
getting the new product out the door.
Prices range from US$699 for the 600 MHz version down
to US$324 for
the 500 MHz version.
Pushing up the speed and power of computer systems
does not always go
smoothly, however?not even for market leader Intel. For instance:
- Don?t even think about it?
Combining Intel?s low-cost 810 chip set with the company?s high-end
Pentium III processor. Due to an error in the P-III?s new multimedia
set, known as MaskMovQ, the P-III simply will not work with
built around the 810 chip set. And while Intel has released a
for the MaskMovQ error, it doesn?t support the fix with the 810 series,
claiming that chipset was designed as a low-cost system for the
Celeron processor. Intel spokesperson Dan Francisco suggested, to
that use of a P-III processor with an 810-based motherboard could
in a hung system. He, however, suggested that some fringe
aiming for a cost-advantage might just go ahead and produce such a
The 810 integrates 3D graphics, and allows for
modem and audio functions. Reports are that Intel will be launching
other chipset models (810E, 820, and 840) in September, along with 600
MHz P-III and Xeon CPU models. The 820, code-named Camino, is expected
to offer a 133 MHz system bus, along with 4X AGP video support, and is
designed to be Intel?s mainstream product line. In the meantime, the
810 chipset will work as advertised with current 466 MHz and upcoming
August) 500 MHz Celeron processors.
- Faster RAM? Maybe not this year
Widespread adoption of the 820 chipset models, however, may take
a while?the faster system bus speed requires faster memory. Intel had
counting on use of RDRAM (Rambus Dynamic RAM) as the answer, but
at the spring Computex Trade Show in Taipei were that high prices and
performance for RDRAM was leading to a reluctance by motherboard
to leap into production. RDRAM, currently running at 400 MHz, and with
the potential of running as fast as 1.6 GHz, has been touted by Intel
the way systems could leap past limitations in system performance tied
to RAM speed.
Early systems based on the 820 chipset will instead
use current 100
MHz SDRAM, trading performance for a pricing advantage?especially with
some manufacturers suggesting that the improvements due to the use of
simply are not dramatic enough to justify the increased cost.
Waiting for USB version 2, that is. While the first-generation USB
has been slow to gather momentum, there are already concerns about its
12-Mbps data rates, limiting it to relatively low-speed devices.
Apple-developed Firewire (aka IEEE 1394) has been touted for disk
digital video, and more. USB 2.0 promises 120-240 Mbps, however?not up
to Firewire?s potential of 800 Mbps, but still plenty hot, especially
with backward compatibility with generation-1 USB devices. The problem
becomes one of too many choices. Should a digital camera manufacturer
for RS-232 serial port? USB (1 or 2)? Firewire? SCSI?
Pretty soon, high-end PCs may be offering parallel,
serial, USB, Firewire,
Ethernet, SCSI, and infrared ports?confusing for the user and for
manufacturers alike. Add in redundant PS/2 mouse and keyboard ports.
PC manufacturers will instead follow Apple?s example (and Microsoft and
Intel?s advice) and simplify, dumping parallel, serial, and PS/2 ports
entirely, while making SCSI and Firewire optional for higher
(and higher priced) models.