(Over)clocking - 266 MHz
There are some questions which lead me to do some additional benchmarks: Is the performance difference between a K6-2 and a Pentium II at higher clock speeds still the same as with 266 or 300 MHz? How clock-sensitive is the 3Dnow! Instruction set? Does the K6-2 become faster than a Pentium II at even higher clock speeds or will the faster L2 cache of the Pentium II be more advantageous?
The 266 MHz version of AMD's K6-2 cannot benefit from the 100 MHz bus speed; that's the main reason for the quite low benchmark results. The deficit compared to a Pentium II 266 is about 11%. Clocking it with 250 MHz and 100 MHz bus speed is the alternative - and the performance results do not differ so much now: The K6 is only behind by 5%.
This chart shows incoming to be memory clock sensitive. Clocked at 266 MHz, the K6-2 is about 4% slower than a Pentium II 266. At 100 MHz bus speed and 250 MHz, the K6-2 is even faster by 5%.
Quake II is also bus clock sensitive: The 66 MHz setting is 15% slower than the Pentium II, even with the special Quake II 3DNow! drivers. The defecit shriks to little 2% with 250 MHz and 100 MHz FSB again.