inbound - 11:47 am on Jul 27, 2010 (gmt 0)
The elephant in the room is mechanical hard drives, some companies use hundreds or thousands in elaborate configurations to increase the number of input/output operations per second and transfer speed (as waiting on data is the big delay for many intensive tasks).
Companies could save a lot of power and hassle by switching to enterprise solid state storage (usually pcie connected). a single one of these devices can solve the issue that people pay a lot of cash for (if it's just iops you are looking for and not loads of storage) - this means you can do more with a single box, thus utilising that cpu power to its full potential.
The CPU of choice (if you need tons of really fast memory too, up to 192GB in a dual cpu server) has to be the Xeon 56xx series or (if you have really high memory demands) there's the 75xx series (up to 1TB on a dual CPU system!)
Of course, most people don't need such systems for web serving - but there are a lot of servers out there that are inefficient that are doing number crunching and those should be power/performance optimised too.
I see a growing market for server acceleration specialists.