OpenThread memory requirements

This page provides information about the layout and the amount of flash memory and RAM that is required by samples that use the OpenThread stack. Use these values to see whether your application has enough space for running on particular platforms for different application configurations.

How to read the tables

The memory requirement tables list flash memory and RAM requirements for the Thread CLI sample that was built with OpenThread pre-built libraries.

The values change depending on device type and hardware platform. Moreover, take into account the following considerations:

• The sample was compiled using:

  • The default prj.conf configuration file and the corresponding Kconfig options CONFIG_OPENTHREAD_NORDIC_LIBRARY and CONFIG_OPENTHREAD_THREAD_VERSION selected. See the Select OpenThread libraries documentation for more information on the Kconfig choices.

  • The CONFIG_ASSERT Kconfig option set to n.

• Values for the Thread CLI sample, which works with all OpenThread calls, are the highest possible for the OpenThread stack using the master image library configuration.

The tables provide memory requirements for the following device type variants:

• FTD - Full Thread Device.

• MTD - Minimal Thread Device.

Some tables also list a master variant, which is an FTD with additional features, such as being able to have the commissioner or border router commissioning roles. See Thread device types for more information on device types, and OpenThread commissioning for more information on commissioning roles.

nRF54L15 DK RAM and flash memory requirements

The following tables present memory requirements for samples running on the nRF54L15 DK with the cryptography support provided by the CRACEN driver.

Single protocolMultiprotocol

nRF54L15 single protocol Thread 1.4 memory requirements

	master	FTD	MTD
ROM OT stack + App [kB]	478	365	312
ROM Bluetooth LE stack [kB]	0	0	0
Persistent storage [kB]	32	32	32
Free ROM [kB]	1014	1127	1180
RAM OT stack + App [kB]	103	93	79
RAM Bluetooth LE stack [kB]	0	0	0
Free RAM [kB]	153	163	177

nRF54LM20 DK RAM and flash memory requirements

The following tables present memory requirements for samples running on the nRF54LM20 DK with the cryptography support provided by the CRACEN driver.

Single protocolMultiprotocol

nRF54LM20 single protocol Thread 1.4 memory requirements

	master	FTD	MTD
ROM OT stack + App [kB]	446	333	280
ROM Bluetooth LE stack [kB]	0	0	0
Persistent storage [kB]	32	32	32
Free ROM [kB]	1558	1671	1724
RAM OT stack + App [kB]	94	85	71
RAM Bluetooth LE stack [kB]	0	0	0
Free RAM [kB]	418	427	441

nRF5340 DK RAM and flash memory requirements

The following tables present memory requirements for samples running on the nRF5340 DK with the cryptography support provided by the CRACEN driver.

Single protocolMultiprotocol

nRF5340 single protocol Thread 1.4 memory requirements

	FTD	MTD
ROM OT stack + App [kB]	333	279
ROM Bluetooth LE stack [kB]	0	0
Persistent storage [kB]	32	32
Free ROM [kB]	659	713
RAM OT stack + App [kB]	97	83
RAM Bluetooth LE stack [kB]	0	0
Free RAM [kB]	415	429

nRF52840 DK RAM and flash memory requirements

The following tables present memory requirements for samples running on the nRF52840 DK with the cryptography support provided by the CRACEN driver.

Single protocolMultiprotocol

nRF52840 single protocol Thread 1.4 memory requirements

	FTD	MTD
ROM OT stack + App [kB]	363	308
ROM Bluetooth LE stack [kB]	0	0
Persistent storage [kB]	32	32
Free ROM [kB]	629	684
RAM OT stack + App [kB]	89	75
RAM Bluetooth LE stack [kB]	0	0
Free RAM [kB]	167	181