config.txt

#overclocking extreme
arm_freq=1100
core_freq=550
sdram_freq=600
over_voltage=8
over_voltage_sdram=6
force_turbo=1

dtparam=spi=on
dtparam=i2c1=on
dtparam=i2c_arm=on
#forcing HDMI output at TFT screen resolution to be able to make the FB copy
#resolution configuration
hdmi_force_hotplug=1
hdmi_cvt=320 240 60 1 0 0 0
hdmi_group=2
hdmi_mode=87
# working config for speed
# 900 Mhz -> 48000000
# 1Ghz -> 35000000
#modification of the speed
dtoverlay=pitft22,rotate=270,speed=60000000,fps=40