Rich,
During some of my tests, I've noted a marked decrease in cutting ability as the chain approaches the speed of sound, or approximately 750mph. (about 26,500 rpm with a 30-pin ½" sprocket) Near as I can tell, the shock wave builds up in front of the cutter and interferes with direct contact with the wood fiber (which, under such pressure, bends out of the way?). But the cutter itself is not harmed by operating in that manner. It isn't until approaching the speed of light (about 26,500 rpm with a 26,723,440-pin ½" sprocket, or using the same 30-pin driver, approx. 23,605,705,354 rpm; and oiling <i>does</i> become an issue, Wayne!) that the cutter itself starts to be detrimentally affected.
Glen