Power Consumption: Overclocking To 4.5 GHz
AMD FX-8370E at 4.5 GHz
For some reason, everyone seems to want to hit a nice, round 4.5 GHz when they overclock. We're not going to be the exception, even though it might not be an efficient approach to tuning AMD's Vishera core. Really, this CPU can go higher. We even managed 5 GHz long enough to boot into Windows. That required an unsafe 1.5 V though, which is unreasonable for running benchmarks.
The core voltage at 4.5 GHz was set to 1.315 V in the BIOS, resulting in an actual reading of 1.26 V. This is already quite high, even though it’s still a lot more manageable than 1.5 V.
At 116 W for the CPU and VRM combined, AMD's FX-8370E is still doing well, especially since the CPU’s contribution is probably under 100 W.
It's annoying that the motherboard and its voltage regulation circuit hit almost 80 degrees Celsius, though. If massive overclocking is your goal, then a more efficient platform would help.
In light of the previous findings, especially the relatively moderate power consumption, a CPU package temperature of 47 degrees Celsius isn't surprising. The processor's heat spreader registers 53 degrees Celsius according to the sensor under it, which isn’t much higher.
The infrared snapshot shows us that a big aftermarket cooler is capable of handling the FX processor's thermal load. Its two fans remain barely audible.
Does it make sense to run at a higher clock rate, trading better performance for increased power consumption? The answer isn’t clear-cut. We do see that the CPU speeds up while essentially consuming the same amount of power when it’s overclocked to 3.5 GHz. This is achieved with mostly untouched BIOS settings and a manual Vcore configured to match AMD's stock reading. Then there's the sweet spot (the point beyond which efficiency starts to decrease). We calculate this to land right around 3.8 GHz. And once you crest 4.2 GHz or so, overclocking AMD's FX-8370E probably doesn't make much sense. It mostly wastes electricity.
Again, if you're gunning for the sweet spot, it's right around 3.8 GHz. That's where you'll get sub-90 W power consumption and respectable performance. If you care more about benchmark results than your power bill, consider calling it a day around 4.2 GHz. Yes 4.5 GHz and higher is possible, but at a certain point you're going to spend too much on a beefy motherboard and high-end cooler, negating the value of overclocking outright.