There has been another gigahertz race quietly brewing, however. This is the race of underdogs, the race to see which value processor would first cross the gigahertz barrier. As you may have surmised from the subject of this review, AMD has taken the prize once again, bringing the 1GHz Duron to market while Intel's value answer, the Celeron, sits at 900MHz.
While this second gigahertz race hasn't garnered nearly as much attention as the first, there are other factors at work that make this a very interesting development indeed. First, Intel has finally started doing what enthusiasts have been for years; namely, running the Celeron on a 100MHz front-side bus. Intel has long been criticized for leaving the Celeron languishing on a 66MHz bus while the Duron has been running on a 100MHz bus since its introduction, so this change should hopefully level the playing field some for the Celeron.
Of course, in case you hadn't noticed by the four digit clock speed, the Duron hasn't exactly been standing still, and the changes on the AMD side are arguably even bigger than Intel's bus speed bump. The 1GHz Duron marks the changeover from the old Spitfire to the new Morgan core.
Spitfire is to Thunderbird...
First, let's talk in general terms about what the implications of Morgan. You'll recall that the current mainstream Athlon core is the Thunderbird, and the current Duron core is the Spitfire. (The Duron is derived from the Athlon, so these core designs are closely related.) AMD has since released an improved Athlon core, named Palomino. The Palomino core brings several things to the table, among them some design changes that result in a reduction in heat, as well as some performance enhancements. The Palomino is the core design used in the Athlon MP and Athlon mobile designs, and it's expected to replace the current Thunderbird Athlons in desktops, as well.
The Morgan, then, is essentially the Duron version of the Palomino core. It offers the same improvements as the Palomino (we'll get to those improvements in more detail in a moment) but with the smaller L2 cache that has always separated the Athlon and the Duron. While the Athlon and Duron have the same amount of L1 cache (128KB, split as 64KB data and 64KB instruction) the Duron makes do with 64KB of L2 cache compared to Athlon's 256KB.