Remember when a 1.4GHz processor was deemed the world's fastest? Man, that was ages ago. Recently, IBM has laid claim to that very record, with its 5.2GHz z196 processor being the focal point. Of course, we've seen a number of consumer chips hum along at speeds well beyond that (thanks to sophisticated cooling systems, of course), but this here enterprise chip does it without any liquid nitrogen-based assistance.
It has been years ago that Intel hit the 3GHz ceiling with their Pentium 4 chip and since that moment there has been almost no progress in processor clock speed anymore. This z196 is targeted at enterprise applications so I doubt we will see any processors with this speed in consumer application soon. But it is a nice achievement of IBM, who still have their own processor development department which brings out new inventions like the Cell processor and now the z196 every now and then.