Light would travel about 660 millimetres in 0.22 nanoseconds, and the chip is about 25 millimetres on the side, so a beam of light could run a few laps around the chip in one clock cycle, or bounce off the sides 20-30 times. Maybe you wanted to say across the motherboard?
I don't think 4.5 GHz is somehow ridiculous when 3 GHz is routine (and POWER7 was 4.2 GHz). Hundreds of cycles of latency when accessing anything off the chip is now routine - that's the world we live in now. I think that the biggest problem is that IBM is not able to make the investments (especially in semiconductor manufacturing) to match Intel's rate of bringing technology to market. The current POWER7 is a 45-nm device if I remember correctly, and this 22-nm POWER8 is not yet on the market. Intel has been selling 22-nm Haswells for how long now? And of course the POWER7 chips have been up against next-generation semiconductors for most of their life.
EDIT: I see that IBM started selling POWER8 systems a few days ago. That's close to a year later than Haswell, and what's more, this chip is likely to compete against 14-nm processors for most of its lifetime.
I don't think 4.5 GHz is somehow ridiculous when 3 GHz is routine (and POWER7 was 4.2 GHz). Hundreds of cycles of latency when accessing anything off the chip is now routine - that's the world we live in now. I think that the biggest problem is that IBM is not able to make the investments (especially in semiconductor manufacturing) to match Intel's rate of bringing technology to market. The current POWER7 is a 45-nm device if I remember correctly, and this 22-nm POWER8 is not yet on the market. Intel has been selling 22-nm Haswells for how long now? And of course the POWER7 chips have been up against next-generation semiconductors for most of their life.
EDIT: I see that IBM started selling POWER8 systems a few days ago. That's close to a year later than Haswell, and what's more, this chip is likely to compete against 14-nm processors for most of its lifetime.