CPU frequency up to 2GHz?

Back then when @balbes150 thankfully tested for me I was not aware that S912’s boot blob wants to play little.LITTLE (it’s an octa-core A53 design with two little clusters so there’s no big.LITTLE here, it’s just Amlogic for whatever funny reasons shipping this SoC with a firmware that artificially limits 4 CPU cores to 1.0 GHz and 4 CPU cores to 1.4 GHz while faking the clockspeed readouts of the faster cluster for whatever reasons)

So when a load like sysbench is running that neither depends on external memory bandwidth nor on anything else happening outside the CPU cores the result with an 8 thread load is an average 1.2 GHz clockspeed and that was exactly what sysbench reported back then.

In reality the situation with S912 is much worse since while with a full load on all 8 cores at least all 4 ‘fast’ cores at 1.4 GHz are utilized with normal workloads that are single-threaded it can happen easily that a demanding task ends up on one of those bottlenecked CPU cores then limited to 1000 MHz.

On average tasks that are single-threaded are slower on Vim 2 than on Vim since on the latter all 4 CPU cores are allowed to clock at up to 1.4 GHz while on Vim2 for whatever funny reasons the scheduler keeps tasks on the artificially bottlenecked CPU cores and limiting single-threaded loads to 1 GHz.

See S912 limited to 1200 MHz with multithreaded loads - #71 by dukla2000

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