Overclocking the Ryzen 9 9900X:
Overclocking the Ryzen 9 9900X via PBO :
There are several techniques for overclocking an AMD Ryzen processor. The first is to activate “Precision Boost Overdrive 2”, more commonly known as “PBO”, in the BIOS. This is automatic overclocking, which will lift certain restrictions and therefore increase the processor’s performance, but at what cost! We wanted to make it clear that using PBO is more complicated than expected, or at least that it will require a fair amount of adjustment in order to obtain a satisfactory result in terms of both performance and power consumption.
So we carried out a reference test, on the left, with just our memory profile activated. In the screenshot on the right, we have enabled PBO in the BIOS. Let’s have a look at the results.
If we stay focused on the score, it rises from 32930 to 34753 points under Cinebench R23, a gain of 5.5%. So overclocking is effective, but at what cost. If we look at the other Benchmate readings, we see that the temperature rises from 60 to 86°C and the power consumption from 161 to 240 watts. Needless to say, this is becoming very unattractive. It will therefore be necessary to set up PBO as accurately as possible to avoid this situation. We’ll be coming back to a more detailed parameterisation of PBO in the coming weeks, as the current temperatures in our lab are scorching.
Manual overclocking of the Ryzen 9 9900X :
Knowing that our Ryzen 9 9900X boosts all cores at 5000 MHz under Cinebench R23, we’re going to start at 5200 MHz. Before starting manual overclocking, we changed the loadline calibration in the BIOS and chose a level 7. Then on to Ryzen Master, where we’re going to increase the frequency of all the cores and maintain a voltage of 1.15 volts. This will drop to 1.10 volts when the cores of our processor are called upon.
Let’s look at our result at 5200 MHz and how high we’ll be able to go. At 5200 MHz, we obtained a score of 34376 points, fairly close to what we obtained with PBO, but here with a temperature of 60 °C and a power consumption of 170 watts! With the same parameters, we were able to climb to 5300 MHz and 5400 MHz.
Beyond that, the processor requires more voltage and, in order to pass 5500 MHz, we had to increase the voltage to 1.225 volts, i.e. 1.17 volts during the run. This gave us a score of 36367 points, a gain of 10.6%, while maintaining a temperature of 71°C and a power consumption of 208 watts.
In the coming weeks we’ll be publishing a special report on overclocking ZEN 5 processors, either via PBO or by switching to manual mode.
