IBM Microelectronics yesterday announced that it is now sampling the 100MHz version of the PowerPC 604 chip, offering it at $549 in quantities of 1,000; volume production is due to begin in December. The PowerPC 604 is designed for use in high-end desktop personal computers, mid-range servers and high-performance graphics workstations. Compared with the 601, the 604 has a redesigned floating point unit, separate instruction and data caches and multiple integer units. IBM is offering samples of the 100MHz 601 at $399 and promises volume next month, and it has cut prices on the slower versions. The 50MHz is now $165, the 66MHz is $165 and the 80MHz is $249, for 1,000-up in each case. systems, is available now in sample quantities and is set to begin production. The PowerPC 603, the least powerful member of the family and designed for mobile and energy-sensitive applications, is set to begin production in November, and it will cost $165 for the 66MHz version and $195 for the 80MHz version.