CPU Overclocking Details
If you want to boost performance, you can use the bundled A-Tuning utility. Its start screen lets you choose Performance Mode in which the computer is supposed to be overclocked in some way. We couldn’t check it out, though. After installing a number of utilities downloadable from the ASRock website, the computer began to malfunction as its system disk was always loaded by 100%. We could only get rid of this issue by removing all installed applications, yet it took a Windows reinstall to get the test configuration back to normal. So, the utility is not yet polished off as you can even see in its start screen that tells you that the computer works in Sandared Mode. It must be a misspelled word “Standard” rather than a reference to a Swedish location called Sandared :).
So first let’s see which automatic overclocking options are available in the mainboard’s BIOS. If you enable the new CPU OC Fixed Mode, the Intel SpeedStep Technology and Intel Turbo Boost Technology options will disappear. The frequency multiplier of our Intel Core i5-4670K is always increased to the maximum (x37-x38) in this case even when there is no load. When all of the CPU cores are in use, the clock rate is still 3.6 GHz, so the practical worth of CPU OC Fixed Mode is unclear. As opposed to it, the Multi Core Enhancement option always sets the CPU frequency multiplier to the maximum value which is normally reserved by the Intel Turbo Boost technology for single-threaded loads only. For our CPU, it means that the clock rate is 3.8 GHz at any load instead of varying dynamically in a range of 3.6 to 3.8 GHz.
Then, you can use Load Optimized CPU OC Setting to automatically overclock your CPU to a predefined level in a range of 4.0 to 4.8 GHz stepping 200 MHz. If you choose Turbo 4.0GHz or Turbo 4.2GHz, the input CPU voltage will be increased to 1.9 volts. Besides that, the option of compensating for the CPU voltage drop is set to its maximum while the voltage on the CPU cores is increased by 0.020 and 0.050 volts, respectively, in adaptive mode. If you choose Turbo 4.4GHz or Turbo 4.6GHz, the voltage is fixed at 1.230 or 1.3 volts, respectively. We didn’t try Turbo 4.8GHz because our CPU is just not capable of such achievements. Thus, you can safely use Load Optimized CPU OC Setting to overclock your CPU just a little, to 4.0 or 4.2 GHz, but such overclocking is hardly optimal because you can get much better results by adjusting the frequency and voltage manually.
First we wanted to check out if the ASRock Z87 Extreme4 could be overclocked without any volt-modding, so that Intel’s power-saving technologies were all up and running. In our tests of the Gigabyte GA-Z87X-D3H we found such overclocking possible, and our result of 4.3 GHz was even very good for a Haswell processor. It is indeed possible with the Z87 Extreme4 as well, but not in an easy way. First, you increase the CPU frequency multiplier to x43. The power-saving options change to Auto at that, so you have to manually set them back at Enabled. Then you lower the CPU voltage from 1.9 back to the standard 1.8 volts. The CPU voltage drop counteraction gets enabled as well, but it is not necessary, so you turn it off. The memory voltage is lowered from 1.6 back to the standard 1.5 volts. Then you must explicitly specify the default voltage on the CPU cores. If you don’t do that, the voltage will be automatically increased to very high levels, making any overclocking impossible. The problem is that the standard voltage varies between CPU samples, so the exact value has to be found by trial and error. Overall, it’s very different from the Gigabyte mainboard where you only have to increase the CPU frequency multiplier and set the CPU voltage at Normal. You don’t have to do any guessing and reset any options to their original values after they get changed by the mainboard, as with the Z87 Extreme4.
So again, even though the Z87 Extreme4 can be overclocked in an energy-efficient way, it is quite challenging, just because its BIOS parameters are tied to each other in a pretty complex and often very sophisticated manner. We used to criticize MSI mainboards for that. When configuring them, you often had to be very cautious about double-checking and triple-checking every parameter after changing just one of them. It is very tiring, but we have to do this to avoid any inaccuracies in our tests. If an important parameter is changed by the mainboard automatically, it may influence its performance greatly. So now we have the same concern with ASRock mainboards. Instead of a smooth and easy overclocking experience, you have to constantly stay alert and continuously recheck everything.
Besides the abovementioned changes the ASRock Z87 Extreme4 automatically makes in its BIOS when you overclock the CPU, there is another one: the fan regulation mode is changed to Full Speed. Of course, an overclocked CPU needs good cooling, but the noise level gets too high without any real reason. The cooler can easily cope with the overclocked CPU at low loads even while working at reduced speed. And when the CPU load increases, the automatic speed adjustment system will speed the fan up. As we’ve mentioned above, the previously existing issues with ASRock’s fan management have been corrected on the new mainboard. So, we can switch the fan back to the standard speed mode and everything works nice until we enter the BIOS again, in which case the speed adjustment system turns off and the fan again starts to work at its full speed.
As opposed to the other options changed by the mainboard automatically, this option is only remembered by the mainboard until your access the BIOS interface. And we have to access it many times while looking for optimal overclocking settings. And every time we do that, we have to switch CPU Fan 1 & 2 Setting from Full Speed to Standard Mode in the H/W Monitor section. If we forget to do so, the fan will scream at its maximum speed after the next system reboot. Fortunately, we found out that the mainboard ceased to change the fan regulation mode in this way if we chose Customize instead of a predefined mode.
Once we have gone through all the numerous steps, we could appreciate the fact that the ASRock Z87 Extreme4, like the earlier-tested models from ASUS and Gigabyte, overclocked our CPU to 4.5 GHz with the voltage fixed at 1.150 volts and XMP parameters for the memory modules.
Energy efficient overclocking is only possible if you don’t increase voltage. It will ensure higher performance and, despite the increased power consumption, you can expect long-term savings due to the reduced amount of energy spent for each computation. Energy efficient overclocking is going to be environment-friendly as we showed in our article called CPU Overclocking vs. Power Consumption. However, when we test mainboards, we want to check them out under different conditions and loads, so we choose what overclocking method ensures the highest results. Higher clock rates and voltages mean harsher test conditions and it is under such conditions that we can better see any flaws or problems in mainboard design, if any exist.
When the CPU voltage is fixed at a certain level, some power-saving technologies stop working, so the voltage isn’t reduced at low loads. We have to put up with that for the time of our tests, especially as it doesn’t affect the computer’s idle power draw much.