Add the package to the arduino Boards Manager Urls:

• Go to Preferences
  • paste this url in Boards Manager URL: https://raw.githubusercontent.com/dbuezas/lgt8fx/master/package_lgt8fx_index.json
• Go to Tools/Board/Boards manager
  • Type lgt8fx in the search box
  • install lgt8fx

Now the boards appear in the IDE and you can also select the clock speed.

32Mhz is twice as fast as a conventional arduino nano!

• PWM & Timers update
• Fast_IO update
• Automatic prescaler setup
• In Menu support of 1, 2, 4, 8, 16 and 32 Mhz
• Digital Analog Converter
• Voltage References INTERNAL1V024/INTERNAL2V048/INTERNAL4V096/DEFAULT/EXTERNAL (useful for example for analogRead or DAC analogWrite via analogReference(xxx));
• Analog Comparator
• Differential Amplifier
• Computation Accelerator

• Support 32 Mhz and other clock speeds
• Differential Amplifier API
• Better Boards Menu
• Installation via Board Manager Urls

• 32Mhz 32.6mA
• 16Mhz 27.8mA
• 8Mhz 25.4mA
• 4Mhz 24.3mA
• 2Mhz 23.4mA
• 1Mhz 22.8mA

• Core is based on: https://github.com/LGTMCU/Larduino_HSP
• Great place to gather data about this boards: https://github.com/RalphBacon/LGT8F328P-Arduino-Clone-Chip-ATMega328P
• (Chinese) LGT8FX8P_databook_V1.04
• (English) LGT8FX8P_databook_V1.04
• Work on the differential amplifier

I have no association with Arduino, Logic Green, Atmel or anything. I just wanted to have a convenient way to use these boards and get them to work without hacks at max speed