From 613b9080d71971c1a65efda2c556eaeb3f8acd21 Mon Sep 17 00:00:00 2001 From: Kristof Robot Date: Mon, 20 Jan 2014 20:37:36 +0100 Subject: [PATCH] README.md: added performance options (resolves #25) --- README.md | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) diff --git a/README.md b/README.md index 074e1ac..543764d 100644 --- a/README.md +++ b/README.md @@ -14,3 +14,36 @@ Maintainers: * Nicolas Aguirre * Enrico Butera * Sergey Lapin + + + +Performance +=========== +The default machine settings are meant to be the lowest common denominator, maximizing generality. +Significantly better performance (2x-3x) can be achieved with the following settings: + +**_Allwinner A20_** + +For Allwinner A20 (Cubieboard2/CubieTruck), the following tuning options are recommended: + +_Enable hardfloat, thumb2 and neon capabilities_ + + DEFAULTTUNE = "cortexa7hf-neon-vfpv4" + +This tuning profile takes advantage of the Allwinner A20 hardfloat, neon and vfpv4 capabilities. + +_Change CPU governor to ondemand, and tune settings_ + + echo ondemand > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor + echo 336000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_min_freq + echo 912000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq + #More aggressive + #echo 1008000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq + echo 40 > /sys/devices/system/cpu/cpufreq/ondemand/up_threshold + echo 200000 > /sys/devices/system/cpu/cpufreq/ondemand/sampling_rate + +This code changes the default CPU governor from _fantasy_ to _ondemand_, and tunes its settings, as recommended at http://linux-sunxi.org/Cpufreq + +For additional discussion, see https://github.com/linux-sunxi/meta-sunxi/issues/25 + +