Manual CPU Overclocking:
To test the ASUS ROG Strix Z390-I Gaming motherboard’s CPU overclocking potential, we set the CPU core voltage no higher than 1.3V and push for the highest stable clock speed. We maintain the DRAM frequency at 3200MHz to take memory stability out of the overclocking equation.
Our particular CPU is not stable at 5.1GHz even with 1.45v. The final stable overclock for almost all Z390 motherboards we may test should be 5GHz, unless there is something particularly wrong with the VRM that limits the voltage or power it can supply. In the case of the ASUS ROG Strix Z390-I Gaming it achieved 5GHz at 1.28 volts with no significant issues.
There are no temperatures sensors which indicate the VRM temperatures so it is unfortunately a guessing game as to how hot the VRMs were operating during testing.
Performance scaled with frequency. On this motherboard where the CPU can follow Intel Turbo guidance the gains from overclocking in longer benchmarks would be more noticeable (effectively going from 4.2GHz all core turbo to 5GHz), since overclocking takes the CPU beyond Intel’s specification. However, if you’d been using the enhanced Turbo mode before overclocking, the jump to a 5GHz all-core frequency, from 4.7GHz all-core, would be less noticeable.
System Power Consumption
We leave the system to idle on the Windows 10 desktop for 10 minutes before taking a reading. For CPU load results we run AIDA64 CPU, FPU, Cache and Memory stress tests and take a reading after 10 minutes. The power consumption of our entire test system (at the wall) is shown in the chart.
Power consumption was as expected, and largely aligns with the ROG Strix Z390-E Gaming.
12-volt EPS Power Consumption
During the 10-minute stress test as specified above, we record the direct CPU power consumption drawn through the EPS 8-pin socket using modified EPS 8-pin cables that have a Tinkerforge Voltage/Current 1.0 bricklet intercepting and monitoring the power flow from the power supply. That bricklet then reports its data to a Tinkerforge Master Brick. All the data collected by the Tinkerforge Master Brick is passed into an external laptop over a USB connection and analysed in the Cybenetics Powenetics Project software.
Power consumption as measured at the CPU 8-pin socket is about right – 104-watts at stock operation and 168-watts under overclocked load. We’d expect to see more like 95-watts for stock operation, but 104-watts is within acceptable margin.