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.
In your Voltage and power settings you are going to want to have a set CPU VCore voltage. You don’t want your motherboard throwing too much voltage at your processor when you are upping the frequency. After some testing we went with 1.30V as a stable VCore voltage. 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.
We ran the AIDA64 system stability test to confirm the system was stable, while it was pretty stable we did notice that our processor would throttle, but AIDA64 did not detect any thermal throttling. Using the Intel Extreme Tuning Utility it told us that our processor was “Motherboard VR Thermal Throttling”. After doing some research it seemed our VRM components were getting too hot. We actually had the same problem with ASRock’s Z390 Phantom Gaming SLI/ac Motherboard. So if you planned on doing overclocking this might not be the board to get.