The main selling point of Intel-based SBCs is higher performance at the cost of slightly higher power consumption. That was also the reason why I decided to buy AtomicPi. Unfortunately, computational benchmarks show that the board not only does not beat ARM-based board, but is even slower. Here is a comparison of performance of APi and Odroids using SciMark benchmark from Phoronix suite. Highlighted are APi and a comparable setup for Odroid: https://openbenchmarking.org/result/1905132-KH-ATOMICPIS21,1905090-HV-1904268HV81&obr_hgv=Odroid+Ubuntu+18.4+LTS+GCC+7+Linaro&obr_sor=y&obr_rro=y&obr_hgv=Odroid+Ubuntu+18.4+LTS+GCC+7+Linaro
The board was powered from a lab power supply, so I could monitor current draw.
Even for benchmarks using all 4 cores at 100% load the measured current never exceeded 2A, current limit set to 3A never activated (so even at peak the draw never exceeded the limit), and core temperatures indicated by sensors
, even for the most computationally intensive benchmarks, were in the range 55C-58C. Voltage measured on the contacts of the Molex power plug (on the big breakout board) was holding at steady 5 volts. Based on that it's safe to assume that the CPU was not throttled.
In most of the (except FFT) tests AtomicPi was either the slowest board, or very close. It's not clear which Odroid board boards were used for testing, but even for the most powerful, XU4 the results are rather surprising.
One thing I noticed is that the processor does not run at full speed. Max CPU frequency reported by cpufreq-info
was 1.68GHz, much slower than highest reported clock frequency 1.92GHz. Is the cpu speed limited in bios to reduce power draw? Is there a way to unlock full performance?
The board is running stock Ubuntu 18.04.1 LTS with kernel 4.15.18-dli, with all system updates installed.