Monday, September 18, 2000

The AMD classic Athlon 1Ghz

Contrary to previous Athlons, the Athlon 1GHz draws 1.80v, rather than the 1.70v of the 850MHz/900MHz/950MHz Athlons, or the 1.60v drawn by the rest of the Athlon family. Asides from that, however, only the 1GHz's L2 cache distinguishes it by operating at 1/3 divider. Thus, instead of using a 1/2 divider and work at 350Mhz like on the 700Mhz processor, the 1Ghz Athlon use a 1/3 divider and uses an L2 cache working at 333Mhz. As a fact, the 700Mhz Atlon was the last Athlon to use a 350Mhz cache.

Like the Athlon 750MHz, and all those that followed it, the Athlon 1GHz incorporates the K75 processor core, and was manufactured using a 0.18 micron process. Thus, the Athlon 1GHz is the 5th AMD CPU to feature 0.18 micron line-widths. The K75 core itself is virtually identical to the K7 core, save for the obvious difference in size, and, was introduced for the first time in the 750Mhz Athlon processor.

In all practical terms, the primary advantage of the smaller core is the corresponding reduction in the amount of heat that the CPU generates.

Among the Athlon 1GHz's distinguishing features, we find 128KB of dual port L1 cache, which is part & parcel of the CPU die, and operates at the same frequency as the CPU core. One thing to keep in mind about the Athlon's L1 cache is that it is divided into 2 parts, 64KB of which is used to store instructions, 64KB to store data.

The Athlon also uses the Digital Alpha's EV6 bus, which operates at 100MHz, but transfers data on both the rising & falling edges of every clock cycle (DDR, or Double Data Rate) - thereby effectively operating at 200MHz. Finally, I'd like to note that the 1GHz Athlon comes equipped with a pair of fans mounted directly on its heatsink. As you can guess from that little fact, the 1GHz Athlon generates alot of heat, and thus requires alot of cooling and accordingly, alot of space...

Next: The AMD Athlon processors