>Will VFP 5 run signficantly faster with the K6-200 mhz chip compared to the Intel 166 non-mmx chip?

The K6 will outperform the 166 by a sizable (15-20%) margin, assuming that other things like disk I/O aren't the bottleneck in your system's throughput. The K6, in addition to having the MMX instruction set, has a larger L1 cache and better integer (non-floating point) optimization than the Intel P54C family did; it's on a par with the Intel 200MMX as far as system throughput (the 200MMX will giuve better performance on FPU and MMX instructions, the K6 generally outperforms the 200MMX on the standard instruction set benchmarks.)