There definitely is more wear at higher RPM: higher pressures, higher vibratoins and higher temperatures will cause metals, oils and fuel to behave differently than at lower temps. I used to race cars and the engines would be rebuilt every 50 hours. The pros would rebuild every 20 hours. The Porsche Cup Car race engines are more-or-less identical to the street GT3 engines. I probably have over 1000 hours on my street GT3 and while I haven't dyno'd it, subjectively, it is not in any need for a re-build. The difference of course is that a race car is run very hard: it is close to redline or it is braking. So you can run at full throttle for extended periods, it just means your engine wears out sooner.