Cpu temperature and fan speed

The static power consumption of the LS1088 is quite a bit higher than the RPI3 due to it’s high speed interfaces (DDR4, PCIe3, 10G etc) but there are some things we can do to reduce it.

There is a cpufreq driver for this CPU (qoriq-cpufreq) but in my previous experience it doesn’t seem to be effective at power reduction.
(the power consumption remains the same, so maybe it doesn’t change all the related clocks)

BUT if you don’t need the full power of the CPU, you can try reducing it’s speed to 1200MHz by flashing a different BL2/RCW. We also setup U-Boot to reduce the CPU voltage slightly to 0.9V (from 1.0V). The DDR and internal CPU bus speeds are also reduced.

If you flash these two files from recovery or via a OpenWrt on NAND:
bl2_qspi.bpl 1200MHz version
fip.bin (U-Boot) with 1200MHz voltage scaling

mtd erase bl2 && mtd write bl2_qspi.pbl bl2
mtd erase bl3 && mtd write fip.bin bl3

Your CPU will startup at 1200MHz and have it’s voltage reduced on the next boot:

SoC:  LS1088AE Rev1.0 (0x87030010)
Clock Configuration:
       CPU0(A53):1200 MHz  CPU1(A53):1200 MHz  CPU2(A53):1200 MHz
       CPU3(A53):1200 MHz  CPU4(A53):1200 MHz  CPU5(A53):1200 MHz
       CPU6(A53):1200 MHz  CPU7(A53):1200 MHz
       Bus:      500  MHz  DDR:      1600 MT/s
..
VID: CPU Core readback: 14

We have been deploying 1200MHz as part of a customer project for a while now without any significant issues. I would be interested to hear any other experiences with it.