Overclocking on the Z390 platform is pretty much the same as it was on the Z370 platform. So if you are familiar with that, overclocking your 9th gen Intel processor will be pretty easy. We are going to do all of our overclocking in the BIOS.
In our BIOS the first thing we are going to want to set is the CPU Ratio mode to “All Core” and the “All Core” ratio to what we are going to shoot for. In our case it is 51, which will bring all of our cores to 5.1 GHz. Also if your BCLK is set at “Auto” it is a good idea to set it at “100.00”.
On the same page in the ASRock BIOS you’ll find your power limit and current limit settings. Motherboards have built-in power settings that will actually throttle your CPU if you throw too much power at it. To disable these built-in settings you can max out the “Long Duration Power Limit” and “Short Duration Power Limit”. You are also going to want to max out the “CPU Core Current Limit”, typically 255.50 is the max you can set here.
In your Voltage and power settings you are going to want to have a set CPU VCore voltage, we went with 1.35V. You may also want to test different load-line calibration settings.
With these settings we were able to achieve a stable overclock of 5.1 GHz across all eight cores of our Core i9-9900K. It seems the beefed up heatsinks on this board helped out a lot.