Since 2006, i.e.roughly the arrival of Mac Intel, Intel has made great efforts to contain and minimize the power consumption of its processors.
This remains a priority at the foundry on all chips for mobile machines and on which Ivy Bridge has further optimized the consumption.
However, The foundry has changed its tune for future products for desktop computers as well as for Ivy Bridge in the next version, Haswell.
Today, Intel offers three slices of Thermal Design Power (TDP) for its desktop processors, 65W, 95W and 130W which one can add another at 150W for Xeon, the highest consumer. In the future, Intel could add another slice between 150 and 165W for its high performance desktop computer.
It is not that there is less optimization of its processors, but it allows them to increase the number of cores and thus their power while also pushing the frequency of each of them. The goal is to achieve greater speed on applications that can take advantage of every core and also to fight in very powerful machines segment found in small research laboratories and are becoming usually equipped with AMD graphics cards designed to give them a boost.
Likewise, Intel could also create a new slice for Xeon that would reach 180W, enough to supply in the near future, processors with 18 or 20 cores.
This is perhaps the reason that prompted the company to start marketing under its own brand watercooling kits for top-of-the-range Ivy Bridge processors, since this energy is converted into heat and must be dissipated in the best possible conditions and with minimal noise.
Finally, it is important to remember that the TDP is the maximum power the processor can dissipate and it will not use this power constantly. Thus, a possible Mac Pro with two Xeon dissipating up to 360W will consume a fraction when it is idle.