Oops, IBM did it again ...
IBM did the utilisation nonsense again:
That is the utilization rate for the non-virtualized V490 is estimated to be 20% and the utilization rate for the virtualized JS22 is estimated to be 60%. The V490 capacity is therefore estimated as 180x78x20% = 2,808. The JS22 capacity is estimated as 56x84.7x60% = 2,845.92. Therefore the cumulative capacity of the 56 JS22 servers at 60% is > than the cumulative capacity of the 180 V490 servers at 20% utilization.
This is utter nonsense out of two reasons: With this utilisation trick IBM gives themself a neat performance factor of 3. I don´t know where this number comes but any competently administrated datacenter uses their servers at factors way above 20%. And when you really want to play this game: Use T6220 blades. They have LDOMS. And SPECwise they are in the same ballpark than a this p6 blade while using less power. At the end this benchmarketing trick ist just plain stupid. To map it in the real world: Don´t compare numbers of new and old servers (as IBM do it everytime) when you are out to shop new servers. Look at the newest servers of both parties. And you should keep one thing in mind: Staying at the same hardware architecture with the same operating system is way more hassle-free than doing a hardware and operating system migration at once.