To unlock BIOS-coded variables such as the boost duration and power limit, we first need to enter the BIOS and go to Advanced AMD CBS SMU Common Options. Here you will find a lot of things set to Auto by the manufacturer, which means that a default limit value has been set and cannot be changed in the OS by the software. To play it safe, we can change the System Configuration to 54 W, change PPT Control and STAPM Control to Manual, and enable STAPM Boost options. You will see that all the manual values are hardcoded to zero, which means that they are currently unlocked and has no limit. There isn’t much need to touch the voltage controls unless you want to spend hours fine-tuning the system to gain maybe a tiny little more juice out of the computer.
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In Windows, we then use UXTU (https://github.com/JamesCJ60/Universal- ... ng-Utility) to control the performance tuning. By setting an Extreme preset, we essentially push to the very end of what the thermal and electric systems can do in this computer.
First, we test the CPU performance using CineBench R20. Auto mode gives 4564 (multi-core) and 601 (single-core), which is already impressive. The older AM06Pro carrying a 4800U has about 80% computing power of this 6900HX, and the graphics capability is less than 60% of the RDNA2-powered GPU in the current system. Setting the knob to Performance mode gives a slight performance bonus but much heavier noises. What really changes the game is the fully unlocked state. The multi-core performance increases by 20% to 5489 compared to Auto. This score has exceeded many beefy gaming laptops carrying the same chip.
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When the computer is idle, the system power draw from the outlet is 10-12 W. When stressed by FurMark (768p 2X MSAA), the APU package draws 60-62 W with the GPU overclocked to 2.6 GHz. In this state, the outlet reads 100-108 W of power draw. The chip temperature stays around 88 °C.
Using FurMark CPU Burner, the APU package stabilizes at 50 W, with all cores reaching 3.9-4.0 GHz and temperature at 95 °C. Due to the high CPU workload, the chip is thermally throttled. If the CPU and the GPU are burned at the same time, the GPU clock can stabilize around 2.4-2.5 GHz. The CPU clock is reduced to about 1.3-1.4 GHz to make room for the GPU. The APU package draw is at about 74 W, and the CPU temperature stays between 95 and 95.5 °C. The system power draw at the outlet reaches a whopping 119 W, which exceeds the full capacity of the power brick written on the label! It is worth noting that the system is unstable under such an extreme load, and there is a good chance that the power will be dropped after a few minutes.
Conclusions: While the system design can be improved, the AM08 Pro is a competitive performance mini PC that is more than capable of handling everyday tasks and casual-to-mid scale gaming.
Pros:
• High CPU and GPU computing power packed in a small compartment
• Good connectivity with 2.5 GbE
• Easily serviceable and upgradable
• Advanced users can play with the BIOS settings and gain a significant performance increase
Cons:
• The fans are too loud under load and can be optimized with better thermal solutions
• Thermal dissipation in the storage chamber should be improved as there is no airflow to cool the RAM, M.2 drive, and 2.5” SATA drive (which directly stacks on top of the M.2).
• It would be great if the power button won’t rotate with the performance selection knob
Update 7/22/2023
I finally had time to take the machine apart completely and repaste the thermal grise with MX4. The peak theoretical performance further increased due to less thermal throttling, particularly the GPU (+3% due to repasting). CineBench R20 Multi-Core is now 121% of the auto mode, and Basemark GPU is 112% of the auto mode.
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