We measured the power consumption with the system resting at the Windows 7 desktop, representing idle values.
The power consumption of our entire test system is measured at the wall while loading only the CPU using Prime95’s Small FFTs setting. The rest of the system’s components were operating in their idle states, hence the increased power consumption values (in comparison to the idle figures) are largely related to the load on the CPU and motherboard power delivery components.
With the Asus X79-Deluxe motherboard applying a CPU VCore of 1.248V under load, the 4960X system draws a maximum of 212W. That’s pretty impressive for a system featuring a high-performance hexacore processor that operates under forced-turbo conditions.
The 3930K system draws an extra 40W under load, which is around 19% more than the identical 4960X-based machine consumes. With a constant-load system usage of 25 hours per week, the 4960X system will use about £7.80 less electricity than the 3930K-based machine over the course of a year (based on a £0.15 per kWh electricity price).
When both hexacore chips are overclocked (using the same voltage, but different LLC settings), the 4960X demands a substantially lower amount of energy – 145W (33%) less, to be precise. With the same 25 hours per week constant-load system usage, that amounts to an electricity saving of just over £28 per year for the IVB-E system, in comparison to the SB-E machine.
Yes, the 3930K-based system is clocked higher, but that doesn’t translate into better performance. While lowered power consumption is nice, people interested in buying an Intel Extreme Edition chip (or a 3930K-level part, for that matter) are unlikely to show much concern over £28 extra electricity per year (in the above usage scenarios).
What will be of more importance to enthusiasts is the lower CPU temperature that decreased power consumption tends to imply. Let’s check the CPU temperatures.