If you're familiar with AMD's A-series chipsets, you already know that they don't support CPU overclocking. As Buildzoid has proven, BCLK (base clock) overclocking appears to be working just fine on Gigabyte's A520M H motherboard. It's uncertain if other vendors support BCLK overclocking on their A520 offerings or if this workaround is all Gigabyte's doing.
The biggest challenge with BCLK overclocking is finding the settings that ensure the entire system lives in harmony. Ryzen's BCLK is connected to other interfaces, including PCIe, SATA, and USB ports. Raising the BCLK effectively overclocks everything else, which is why overclockers prefer playing with the ratio multipliers more than the BCLK if given a choice. Sadly, only the latter is possible on the A520 chipset.
For the demonstration, Buildzoid overclocked his Ryzen 5 3600 on the Gigabyte A520M H motherboard, which retails for roughly $78 overseas. He highlighted that the motherboard was on the factory F1 firmware. Since that time, Gigabyte has released the F2 firmware for the A520M H, so we're unsure if Gigabyte has patched BCLK overclocking on the newer firmware.
Buildzoid pushed the Ryzen 5 3600 to 4,389 MHz on all six cores by increasing the BCLK to 108 MHz and moving the CPU clock ratio to 40.50. For context, the Ryzen 5 3600 typically has an all-core boost clock the fluctuates around 4.1 GHz, depending on the motherboard, cooling, and the workload.
The hardware enthusiast thinks that BCLK overclocking on the A520 chipset is somewhat linked to AMD's Precision Boost Overdrive (PBO) technology. Therefore, he had to raise the power limits in the XFR (Extended Frequency Range) enhancement section of the motherboard.
In theory, you can overclock more powerful Ryzen chips, such as the Ryzen 9 3950X on AMD's A520 motherboards. It's tempting, but you really shouldn't since A520 motherboards pretty much come with baseline power delivery subsystems that are only designed for running the processor at stock speeds.