Overclocking
To overclock the XFX SPEEDSTER MERC 308 Radeon RX 6600 XT Black Edition video card we are using AMD Radeon Software and the Performance feature.
Unlike some previous AMD video cards, this one allowed us to overclock with plenty of headroom on the sliders. For example, the memory frequency was not locked to a ridiculously low value. In addition, the Power Tuning ability was quite high on this video card, allowing a +20% improvement from 100% to 120%, this is higher than we are usually allowed. We could also maximize the core frequency to very high values with the sliders, and control the fan speed. We set the fan speed to 100% for all the overclocking. The only slider that was locked at maximum value was the Voltage, which was at 1150mV and could not be changed to a higher value.
Our final highest stable overclock we achieved was with the Max Frequency slider at 2800MHz and the memory slider at 2300MHz. This changed the memory frequency up to 18.4GHz from the default memory frequency of 2000MHz or 16GHz. We did try 2400MHz which would make it 19.2GHz, but that was too much, we ended up finding that 2300MHz or 18.4GHz was the right value for stability that allowed us to raise the GPU frequency also as much as we could. The memory bandwidth increased from 256GB/s to 294.4GB/s with the new overclock.
Highest Overclocked GPU Frequency
We will now graph out the overclock of the GPU playing Cyberpunk 2077 at “Ultra” settings in a manual run-through.
In the graph above you can see how the new overclock with the slider set at 2800MHz resulted in while gaming (the orange line.) The increase in frequency was between 2688-2748MHz, or roughly an average of about 100MHz higher than the default. The average overclock frequency is 2737MHz and remember the default average was 2618MHz. That is a roughly 5% GPU frequency overclock or 119MHz average.
We did try to push it higher, but the video card would lock up while gaming above 2800MHz on the slider, it’s possible maybe some games would be playable at just slightly higher than this, but not all games. This overclock represents stability in every game we tried, while we were able to get it just slightly higher in a few, but the rest would lock up quickly. So this is really the best all-around overclock.
GPUz Sensor Data Overclocked
Here is the GPUz sensor data with the video card overclocked. You can see that at 100% fan speed the GPU Temperature is only 53c and the hot spot 71c. The fan speed is 3427RPM and much louder. GPU Voltage stays the same and GPU Chip Power Draw increases to 152W.
