Monday, July 03, 2000

Introduction

Some time in the past, AMD had a reputation for making CPUs that were - at best - flakey. For that reason, many assemblers refused to use AMD processors in their products for quite a long while. All that changed with the arrival of the Athlon, however, and most agree that AMD's new line of CPUs is above reproach. Not only has AMD's new family of CPUs obtained a reputation for performance, and stability, but they've also attained performance-levels so high that Intel - the 800lb gorilla of the chip industry - has begun to really fear AMD as a serious competitor.

Never before has AMD released such a proliferation of processors in as short a time-span as they have in the last few months. This veritable avalanche of AMD Athlon chips has in fact, finally resulted in 1GHz renditions of the Athlon appearing on the market in force. Without further ado, then, let's get down to the business of reviewing the Athlon 1GHz in all its glory.

The AMD Athlon 1GHz

Contrary to previous Athlon processors, the Athlon 1GHz draws 1.80V, rather than the 1.70V of the 850MHz - 900MHz - 950MHz, and the 1.60V of previous Athlons. In fact, it's a fairly well known fact among Overclockers that increasing the voltage supplied to a CPU can greatly increase that processor's stability.

Asides from that particular detail, the only thing that distinguishes the Athlon 1GHz from its siblings is its L2 cache, which has once again undergone a face-lift. In effect the L2 cache of the 1GHz no longer operates at 2/5 the speed of the processor itself, but rather at 1/3 the frequency of the latter. Thus, AMD has implemented an L2 cache operating at 333MHz with the Athlon 1GHz. Why not higher? This was done for economic reasons, as an exterior 512KB L2 cache running at 350MHz or better would be prohibitively expensive.

As with the Athlon 800MHz, the Athlon 1GHz is based around a K75 core manufactured on a 0.18 micron process. The 1GHz is then the 5th AMD process to benefit from the 0.18 micron process. The K75 core itself is slightly smaller than the K7, much as a result of the smaller 0.18 micron process. In practical terms, such a "process shrink" has allowed the Athlon core to be clocked to higher frequencies, while dissipating less heat.

Among other features, the Athlon 1GHz possess 128KB of dual-port L1 cache, which is embedded within the processor-die, and oscillates at the same frequency as the processor's core. The L1 cache is divided into two parts; a 64KB space for storing instructions, and another 64KB space for storing data. As well, the use of the 100MHz-DDR Digital Alpha EV6 bus (which has an effective speed of 200MHz), is still present & accounted for. Finally, I'd like to point out that, contrary to other AMD processors, the 1GHz comes with a pair of fans mounted directly ontop of the included heatsink. As you can probably guess, the 1GHz generates quite a bit of heat, and requires better cooling as a result. The entire assembly takes up a fair amount of space, as the heatsink is anything but "small format". Add in the fans, and you have quite an impressive little monolith. The reason I make mention of this, is that I had some difficulty in actually installing the processor in my AOpen AK72 motherboard. This was due to the ATX connector, which unfortunately is located right next to the Slot A connector. With that in mind, it would be a good idea to check your motherboard to make sure that you have proper clearance, otherwise you could end up being unpleasantly surprised not to be able to install your new Athlon 1Ghz processor...

Next: The tests