Linux Kernel 4.18.8

[dukla2000]

How is your stability/temps at 2/1.5GHz? My plex server sure could use that extra gear.

Short answer - fine  

Long answer: it all depends on cooling/heatsink etc. I have the stock 30mm Pine64 heatsink and no fan. At 1.8/1.4 I can run cpuminer for "a long time" (around 20C ambient) without ever getting to 80C (and so without throttling). At 2/1.5 I get to 80C and start throttling after about 15 minutes. I do have another heatsink on order that I hope will be better than the Pine 30mm one - I am loath to add a fan as the noise irritates me (which is why I was happy to downscale from Wintel!)

Also have not done a complete thrashing of the setup. I am bemused to see in the RockChip specs they mention a RK3399K which is specd at 2/1.6 as long as you keep it between 0-80C, and the RK3399 is 1.8/1.4 0-80C. My particular RK3399 has no K on the heatspreader (and does have what seems to be a January 2017 manufacturing date - 1701) and so I would be pretty sure is a bog standard RK3399. My RockPro64 is from the first 2.1 batch - I can image as volumes rise and purchasing between Pine and Rockchip gets busier this could all change.

Equally I have not yet had cause to play with the voltages but seems there is quite a bit a headroom there: the Rockchip spec is 1.25/1.20V max for the A72/A53 cores. My current DT has 2GHz @ 1.25V but I previously briefly had it at 2GHz @ 1.2V with no big problems. The "standard" RK3399 is apparently 1.8GHz @ 1.2V (in the stock DT) whereas (possibly for the K?) the "standard" device tree has 1.8GHz at 1.15V - at some stage I am tempted to try 2.1 or even 2.2 @ 1.25V. (I am less motivated to play with the LITTLE A53 cores as there is not much to gain for single threaded stuff!)