Power Consumption and Overclocking
Throughout all of our benchmarking and testing, we also monitored how much power our test systems consumed using a power meter. Our goal was to give you all an idea as to how much power each configuration used while idling and while under a heavy workload. Please keep in mind that we were testing total system power consumption at the outlet here, not just the power being drawn by the processors alone.
The Core i5-3470's power consumption characteristics where right in line with, albiet somewhat lower than, the Core i7-3700K. Idle power was slightly higher, but the Core i5-3470's load power was--as expected--somewhat lower.
The Core i5-3470 is not a K-series processor, so it is not fully unlocked, but there are still some sizable performance gains to be had by overclocking. As we've mentioned, the Core i5-3470’s maximum multiplier can be set to only four bins higher than its peak Turbo multiplier. Since the base clock is 100MHz and the Core i5-3470 has a peak Turbo frequency of 3.6GHz, its max stock Turbo multiplier is 36. Through overclocking, that multiplier can be increased to 40, for a peak Turbo frequency of 4.0GHz. Manipulating the base clock can also add a bit more juice, however, to the tune of an additional 5-7%.
Using only the stock Intel air cooler and a modest .1v bump in voltage, we were able to take the Core i5-3470 up to 4.2GHz using a multiplier of 40 and a base clock of 106MHz. Ivy bridge has shown to have much more headroom available than what we've achieved, so as long as you've got decent cooling and a good motherboard, pushing the i5-3470 to its limit should be no problem.
While we had the Core i5-3470 overclocked, we re-ran the Cinebench multi-threaded benchmark and saw a nice increase in performance. The CPU wasn't able to catch the HT-enabled Core i7-2700K, but it was nipping at its heals.
We also monitored power consumption while the Core i5-3470 was overclocked and saw a moderate 47W increase in power consumption.