Power Consumption, Closing Thoughts
We were keen to see how the 4.7GHz overclock affected system power consumption. Since we are operating the Core i3-6100 exactly 1000MHz over spec and had increased the voltage, we expected power consumption to get a little out of hand.
Despite a 27% increase in frequency and increased voltages, the entire system draw was just 25% higher which was surprising. Keep in mind that the Intel HD Graphics 530 engine is disabled when overclocking, so this helps reduce power consumption.
Clocked at 4.7GHz the Core i3-6100 system consumed just 110W in the 7-Zip multi-threaded benchmark. In comparison, the FX-8320E system consumption increased by 71% when boosting the frequency by 31%.
So there you have it, possibly the biggest game changer for enthusiast PC builders and overclockers since Intel released its unlocked-K series processors five years ago.
From what we can determine, it sounds like Asrock will be releasing an updated BIOS for each of their Z170 motherboards to enable base clock overclocking. This creates some attractive combinations. The company's Z170 Pro4, Z170 Pro4S and Z170 Extreme3 all cost $110 and are the perfect pairing for a Core i3-6100 or Core i5-6400.
The Core i5-6400 ($190) has the potential to deliver big things, though it only features a 27x clock multiplier which would result in a 3.4GHz operating frequency if it's limited to the same 127MHz base clock as our Core i3-6100. If that is the case, then spending $10 more on the Core i5-6500 might be a smarter move, as its 32x clock multiplier would allow for a 4.06GHz operating frequency. That said, both processors might have no trouble exceeding the 127MHz base clock, so we'll have to wait and see although Asrock's own overclock of the Pentium G4400 was also limited to a 127MHz BCKL.
Speaking of the Pentium G4400, as tempting as it may appear to get your hands on a $65 Skylake CPU and overclock the hell out of it, we don't believe this is a wise investment in terms of value. The cheapest motherboards that support the BCLK overclock cost $110, so it seems wasteful to invest in a dual-core limited to two threads.
For now the BCLK overclock is relatively easy to perform and we were up and running within minutes. Due to time contraints I have yet to really try and tweak the overclock and I haven't had time to run an endurance stability test, but all of our benchmarks finished without a hiccup. It's safe to assume that almost all Core i3-6100 processors should reach at least 4.4GHz.
Although BCLK overclocking is slightly more complicated than the dead easy multiplier overclocking provided in K CPUs, we suspect in time Asrock and other manufacturers will take things to the next level and include predefined non-K overclocks that will detect the processor used and provide some automatic overclocking options.
Power consumption figures were pleasantly surprising with only a minor increase in draw during the overclock. Often consumption figures get blown up when overclocking and with that so do temperatures. Granted, we were using a Noctua NH-D14, but temperatures never climbed above 54 degrees, which suggests users will get away with affordable air coolers such as the $30 CM Hyper 212 Evo.
The effects this will have on buying recommendations have yet to be seen. It's still early days with Asrock and potentially other motherboard manufacturers (Asus, Supermicro, MSI) working on getting those BIOS updates out the door. Eventually we expect to hear from Intel as well.
But for now, anyone looking to build a Skylake system would be crazy to buy anything but a Z170 motherboard. Intel's Core i7-6700K and i5-6600K seem to be facing a bit of a stock shortage right now, so as we see it, Asrock is doing Intel a favor.