As anticipated (CI No 3,601), Advanced Micro Devices Inc launched its AMD K6-III processor yesterday, a day in advance of Intel Corp’s official launch of the Pentium III. It claimed to have begun volume shipments of the 400-MHz part, with samples of the 450-MHz versions already going to its OEMs, including Compaq Computer Corp. AMD says that, using the Winstone 99 benchmark, the chip outperforms the widely-previewed Pentium III by one speed grade running business and consumer applications. Aside from its existing 3Dnow! graphics instruction set, positioned against Intel’s new Katmai instructions, AMD has added what it calls the TriLevel Cache design to the chip, which it says gives it the largest and fastest total system cache available for Windows-compatible desktop PCs. The addition of TriLevel boosts the K6-III’s performance levels so that a 450-MHz part will outperform a 500MHz Pentium III, says AMD, though the performance increase is only a significant one when comparing chips running at the same clockspeed. TriLevel Cache includes the standard 64KB of Level 1 cache, but also adds an internal full-speed backside 256KB Level 2 cache, and has a 100-MHz frontside bus to an optional external Level 3 cache on the Super7 motherboard of up to 1,024KB. That gives the K6-III a total of 320KB of combined L1 and L2 cache, more than any other x86 CPU, and up to 1,344Kb in total. No other x86-compatibles have the option of an external L3 cache on the motherboard. In comparison, the Pentium III has 32Kb of internal cache and up to 512Kb of half-speed external L2 cache, a total of 512Kb. AMD says its Level 2 cache also runs at full processor clock speeds, and that the design incorporates internal multiport caching, so that simultaneous 64-bit reads and writes of both the L1 and L2 caches are enabled. Compaq said it planned to use the new chips in a faster version of its Presario internet PCs. The 0.25 micron, 21.3m transistor parts are priced at $476 for the 450MHz part, and $284 for the $400MHz part, in quantities of 1,000. The prices are expected to come in under those of Intel.