The Athlon brand name and the products that had this name have been with us for already a long time. This is the story of the CPU that brought AMD the success it needed to seriously compete with Intel in terms of performance and market-share.

In 1998 the CPU business was a crowded place, no less than 5 manufacturers were supplying the x86 CPU market. The largest was Intel, it manufactured the budget CPU Celeron, the PentiumII and would soon release the next generation PentiumIII . AMD had the K6 and K6-2 in their productline. Cyrix was manufacturing the 6x86MX/MII and the MediaGX. IDT´s CPU design subsidiary Centaur was busy with the WinChip2 and new designs were coming up soon and finally RiSE was almost ready to introduce its mP6.

Things seemed to go quite well for AMD, the newly released K6-2 was selling very good and AMD was more or less able to match Intel's clockspeeds. But not all was as it seemed, despite record sales AMD had to report a loss in both 1997 and 1998.
One of the reasons was that AMD's processor line-up was targeted at the mid- and low-end market. Profit margins are low in those sectors. The high-end market has much better margins but Intel roamed supreme there.
Another reason was that AMD had no high volume deals with large PC manufacturers. Those deals provide a steady income but these demand high volume manufacturing. AMD just could not manufacture enough CPU's because it only had one wafer fabrication plant : Fab25 in Austin TX..
AMD had to get its share of the high-end market in order to get better margins on its CPU´s. A superior CPU together with a larger manufacturing capacity would bring AMD the break it needed. But the K6-2 was just not good enough for that plan, they needed a CPU that could match, or better yet, surpass Intel's offerings in terms of performance and price.

AMD´s 7th generation processor, the K7, had the job of beating Intel's next generation CPU. The design team of the K7 consisted of former K5 designteam member and was led by Dirk Meyer. Dirk Meyer had worked for Digital and was one of the designers of the Alpha 21264 CPU. Work on the K7, under the codename Argon, started in 1995 and it took around 17 months to complete the initial design. Early 1998 details started to emerge about the K7. It would use the non-Intel compatible 200MHz EV6 bus licensed by Digital. Also, the CPU itself would be manufactured using copper interconnect technology instead of the usual aluminium interconnects. Clock speeds would be starting at 500MHz, but 1GHz was already mentioned! These speeds were unheard of, most PC's at that time had CPU's with a clockspeed of around 300MHz with a 66MHz bus. With these specs the K7 should certainly be a top performer.

But AMD was not betting on the K7 alone to get them a bigger share of the market. As early as 1994 AMD had plans for a new fab, but it would take until 1998 before construction began. AMD had made a deal with the German government. The new processor plant, Fab30, would be built near Dresden and create hundreds of jobs and the German government would partly finance construction. With the extra production capacity, AMD would at last be able to manufacture more than enough CPU's. Maybe then some large PC manufacturers would close high volume deals with AMD.

In October 1998 on the Microprocessor Forum, Dirk Meyer gave a presentation about the K7 and its features. He baffled his audience with the top performance specifications of the soon to be released CPU. Unfortunately for his audience he did not show a working system.
Not long after the Microprocessor forum, AMD demonstrated a system based on a 500MHz K7 at the COMDEX in November 1998. Behind closed doors a few people got the opportunity to see AMD's 7th generation CPU in action. The system consisted of the Gomez motherboard with an early sample of the K7. On another tradeshow, the CEBIT in March 1999, AMD showed a 600MHz K7 on the Fester reference motherboard.

With all these "secret" presentations of the K7 and the promised top performance, a hype started to form around the new CPU. Many hardware sites and PC magazines wrote articles about the upcoming K7, its specifications and whether it would outperform its rival: the Intel PentiumIII. Also, rumours started to circulate that the K7 would get a name. Like Intel used Pentium, Celeron or Xeon to name its CPU's.
AMD had recently registered several URL's at the time, for instance Alereon and AMDAthlon, which name would it be?

Then, on June the 23rd 1999, finally AMD announced that it commenced shipments of its new 7th generation microprocessor, the AMD Athlon processor! The first Athlon's had a speed of 600MHz, 550MHz and 500MHz and prices were respectively $699, $479 and $324. Initial production would be done at AMD's in Fab 25 in Austin with 0.25 micron 6 layer Metal Interconnect with standard aluminium process technology.
AMD's Athlon processor had a nine issue superscalar microarchitecture which meant it could execute multiple instructions per clockcycle. Other features included advanced branch prediction, fully pipelined FPU, a large 128KB (64KB instruction & 64KB data) L1 cache, an even larger 512KB L2 cache and enhanced 3DNow! instructions. All these features were packed in a 22 million transistor core which at 0.25 micron measured 184 square millimetres.

Other features of the new CPU were the support of cache sizes of up to 8MB, a multiplier for the cache which allowed for maximum cache speed at different CPU clockspeeds (1/2, 1/2.5, 1/3) and the ability of the K7 to be used in multiprocessor setup. Typical power consumption of the K7 at 500, 550 and 600MHz was 38, 41 and 45 Watt respectively.
The name Athlon was derived from the word decathlon. Decathlon is a two day event where contenders compete in 10 sporting disciplines. The contender that performs best overall in all 10 disciplines wins. In short Athlon was chosen to emphasis best performance.

The new CPU was packaged in a cartridge instead of a PGA like the K6. Production techniques at the time weren't advanced enough to implement the L2 cache on the core. The solution was to place the cache in the form of two chips together with the CPU on a small PCB. This PCB interfaced with a 242 pin SC242 connector on the motherboard which AMD named SlotA. Intel used the same method with its PentiumII and early models of the PentiumIII. The connector was actually the same, AMD turned the connector around to make the installation of the CPU incompatible with SLOT1 CPU's.

Not long after the successful launch of the Athlon, news of shortages popped up on several news sites. With the tremendous interest for the CPU this sounds not unusual. But these reports were not about a shortage of CPU's, but shortages of chipsets and motherboards. AMD did not just launch a new CPU, but a whole new platform. Older CPU's like the K5 and K6 were compatible with Intel's chipsets and could thus be used with widely available motherboards with Intel (compatible) chipsets. The Athlon needed its own chipset and this was a major risk AMD took.

Manufacturers of motherboards needed to design new motherboards for the Athlon processor and chipset manufacturers new chipsets. AMD tried hard to convince the manufacturers to support the new platform, but many wanted to wait and see what would happen. Competition was fierce and diverting efforts for an unproven platform was considered a big risk. To get the initial Athlons on the market AMD designed its own chipset, the AMD 750 chipset that was manufactured by UMC. Early motherboards from FIC, MSI and Gigabyte were all based on the 750/751 north-bridge and the 756 south-bridge.
Fortunately VIA was working on its Athlon chipset, KX133, and Ali also announced it would start manufacturing a chipset for the Athlon. But at the launch of the Athlon, only one chipset was available to motherboard manufacturers, the AMD 750.

Since the launch of the Athlon in June 1999 finding the CPU and a motherboard was though. Only in the second half of September of that year the products began to show up in large numbers in retail channels.

Despite the initial problems, the Athlon was lauded and received many design wins. The hardware community went nuts, at last a CPU that could beat Intel's offerings in almost every benchmark. PC manufacturers like Compaq and IBM announced products based on the Athlon, the future looked bright for AMD.

To really be able to compete on every level of the market AMD had to diversify its product line. Intel marketed the Celeron line as budget CPU, the PentiumII/III as standard desktop CPU and the Xeon for use in servers and professional workstations. AMD was working on multiple processor lines, there was talk of an Athlon Ultra, Professional and Athlon Select. But nothing of the likes was implemented at the time.

When compared to the Intel PentiumIII, the performance of the Athlon was superior in every way. This is not that surprising because the design and feature set of the K7 was newer and better. Only when Intel introduced the 133MHz bus with the PentiumIII-EB the performance level between the two was in balance.
Enthusiasts quickly uncovered the overclocking potential of the Athlon to increase the performance even further. The cache multiplier and the feature to manipulate the CPU multiplier via the internal debug connector made overclocking relatively easy. To show how well the K7 would scale in terms of clockspeeds, AMD had already shown a 1GHz system back in April 1999 at the annual shareholders meeting. This system was build around KryoTech's Super-G phase change cooling to keep the CPU temperature below zero.

On 29 November 1999, AMD announced the 750MHz Athlon. This was not just another speedgrade, the 750MHz Athlon was based on a new core revision; the K75, codename Pluto. The K75 core was manufactured at Fab25 in Austin with AMD's new 0.18 micron aluminum process technology. The new 0.18 micron die measured 102 square mm which was considerably smaller that the 184 mm2 of the 0.25 micron K7 die. The smaller die size of the 0.18 micron Athlons increased the number of cores per wafer. This was very important, it meant more CPU's could be manufactured at almost the same costs in overhead thus increase profits.

Another important milestone for the Athlon and not in the least for AMD was the announcement of the 1GHz Athlon. On March the 6th 2000 AMD announced it had reached an industry landmark with the release of the first commercially available 1GHz x86 CPU. Compaq and Gateway would ship the first PC's with the 1GHz Athlon. With the release on March the 6th AMD beat Intel by two days, Intel announced the availability of the 1GHz PentiumIII on March the 8th! The 1GHz Athlons were priced at $1299 which was a premium price. In contrast the 1GHz PentiumIII cost a mere $990.
The 1GHz Athlon was based on yet another core revision, the K75 with the codename Orion. This core revision ran at a slightly higher voltage than the Pluto K75, 1.8v instead of 1.7v.

June 2000 was a very busy month for AMD, several important announcements were made.
First, AMD's newly build FAB30 began production of the Athlon using new copper interconnect technology licensed from Motorola. AMD named its 0.18 micron copper technology process technology HiP6L and used it with 200mm wafers which could hold about 300 cores.
Second, the introduction of another core revision, the Thunderbird, which included 256KB cache on die and a few other tweaks. The new 120 mm2 core had 37 million transistors and was used for SlotA and for the new SocketA processors. The Thunderbird was produced in Fab25 with aluminium interconnects and in Fab30 using the new copper interconnect technology.
Third, the introduction of the Duron processor, a budget CPU that had to compete against the Intel Celeron. The Duron was a SocketA processor with 64KB full speed cache.

AMD had used the SLOTA technology because its production techniques weren't advanced enough to include the cache on the core. With the introduction of the Thunderbird this had changed and AMD was ready to return to the socket again. The new socket was named SocketA and had 462 pins. As a reference, the Socket370 in use by Intel for their PentiumIII and Celeron CPU's had 370 pinns.
The PC enthousiast welcomed the PGA Athlons because it made cooling the CPU much easier. With the heatsink attached directly on the core, cooling would be much more efficient. Unfortunately the core was also vulnerable to damage when installing and removing the heatsink. Many SocketA Athlons "died" because of damage to the core.

New RAM technologies were getting mainstream around 2000 and for the x86 platform this was Double Data Rate or DDR. To be able to bring DDR for the Athlon and so helping market acceptance and enhancing performance, AMD designed the AMD 760 Iron Gate chipset. But AMD was also talking with RamBus which was designing an even more advanced RAM Technology. There was never to be a deal between the companies because of the costs and the reluctance of consumers to use RIMM. Intel tried to push the technology, which was a better option than DDR except in price, but it failed miserably.

The release of the Athlon CPU was a big risk for AMD, mainly because it required a whole new non-Intel compatible platform. Many factors, which not all have been discussed here, made the Athlon a succesfull CPU. Not in the least the fact that AMD had produced a real 7th generation CPU with new technologies through hard research and design work. And we should AMD thank for that! When the Athlon was introduced many of the other x86 CPU manufacturers had stopped with their efforts and left the x86 business. Essentially AMD was the only x86 CPU manufacturer that kept Intel from overpricing its products.
With sales of the Athlon gaining momentum, Q4 of 1999 was closed with a profit of $71 million and AMD predicted operating profits for 2000 after 4 years of losses.

Relevant press releases :
- AMD Discloses Next-Generation AMD-K7 Processor Microarchitecture at Microprocessor Forum
- AMD Ships the World's Fastest x86 Microprocessor
- AMD Introduces The 650MHz AMD Athlon Processor, The Fastest, Most Powerful Engine For x86 Computing
- AMD Ships World's First 700MHz x86 Processor
- AMD Athlon Processor Sets New Performance Leadership Mark At 750MHz Built On Advanced 0.18 Micron Technology
- AMD Demonstrates 1.1GHz AMD Athlon™ Processor
- Fall Deeper in Love with the Worlds' Fastest x86 Processor: The 850MHz AMD Athlon Processor
- AMD Athlon Processor Rockets to 1 GHz
- AMD Announces First Revenue Shipments From Dresden "MEGAFAB"
- More Products, More Performance, More Partners: AMD Unveils New AMD Athlon™ Processor; Commences Shipments of AMD Duron™ Processor

Overview of models, speeds and cache :
- K7 : 500-700MHz, 512KB cache
- K75 (Pluto) : 550-850MHz, 512KB cache
- K75 (Orion) : 900-1000MHz, 512KB cache
- Thunderbird (SlotA) : 650-1000MHz, 256 cache
- Thunderbird (SocketA) : 650-1400MHz, 256 cache

External links with information about the Athlon :
- AMD Athlon page
- Tomshardware, The New Athlon Processor: AMD Is Finally Overtaking Intel
- Aceshardware, The Athlon 650 Takes On Intel's Heavyweights

Part 2, The Athlon XP, coming soon
Part 3, The Athlon is dead, long live the Athlon64! coming somewhat later

All AMD Athlon pictures