Power, Heat, And Efficiency
Previous CPU-specific articles have already proven that Intel’s new processors are far less power-hungry than previous models, but some of that power savings will certainly be offset by the new build’s more power-hungry graphics cards.
The first part of the power chart that stands out is the new system’s idle power, which is barely affected by overclocking when C-States are enabled. The current overclocked system has similar load wattage to its non-overclocked predecessor.
Disabling C-States forced full-voltage and frequency to full-time status, costing around 46 W at idle and, surprisingly, 26 W at full CPU load. That’s really important this time, since appreciable performance benefits were limited to storage benchmarks.
Power consumption was so low on today’s overclocked build that we could easily have added a third graphics card, if only the power supply had the extra connectors for it. For those who would like to add a third card to this build, we recommend using at least one native PCIe power lead for each card and reserving the use of adapters for each card’s second power input. An 8-pin-to-dual-6-pin PCIe power splitter should supply enough current to supplement the second PCIe power input of two cards, while a dual-4-pin (drive)-to-single-6-pin (PCIe) adapter can supplement the third card’s second input.
Manual fan adjustment was required to overcome the poor thermal management of these cards when overclocked. Occasionally, the cards would even encounter a thermal lockup at stock frequency. A third-party fan controlling utility, such as the one built into MSI Afterburner, would have allowed a lower target temperature. But those who prefer not to use such utilities will find that AMD’s Catalyst fan control sufficient. A Catalyst fan setting of 40% explains the lower GPU temperature in the current build’s overclocked configuration.
The current build is 31% more efficient than the previous $2000 PC at stock speed, thanks to a 12% performance increase at 15% less power. Overclocking increased its performance by a greater amount than its power consumption, leading to improved efficiency at higher frequencies.
Hard drive, game, encoding, and productivity benchmarks each make up 25% of our performance average, while idle, CPU, GPU, and combined power each contributing 25% to our average power rating. Improved hard drive performance is primarily responsible for the current build’s 9% gain with C-States disabled, while lower idle power is the biggest contributor to its 2% efficiency gain with C-States enabled.
