Intel Corp. and Advanced Micro Devices, fierce rivals in the market for microprocessors, are expected on Monday to announce their fastest-ever chips, analysts said, continuing the pair's long rivalry. Advanced Micro Devices   will debut its Athlon XP 2000+, which runs at 1.67 gigahertz, or 1.67 billion cycles a second, while Intel will unveil its new Pentium 4 chip running at 2.2 gigahertz, analysts said.