Embedded Systems Memory Guide — Raspberry Pi, Arduino & SBCs (2026)

Single-board computers (SBCs) and embedded systems like Raspberry Pi, Arduino, and NVIDIA Jetson have become essential for hobbyists, educators, and industrial applications. Unlike traditional PCs, these devices have unique memory constraints. This guide covers what you need to know about memory in the embedded world.

Table of Contents

Raspberry Pi Memory Specifications

Raspberry Pi models come with fixed, soldered LPDDR RAM that cannot be upgraded. Choose the right model at purchase time.

Model	RAM	RAM Type	Storage	Use Case
Pi 5 (8GB)	8GB	LPDDR4X-4267	microSD / NVMe (via HAT)	Desktop replacement, media server, AI
Pi 5 (4GB)	4GB	LPDDR4X-4267	microSD / NVMe (via HAT)	General projects, home automation
Pi 5 (2GB)	2GB	LPDDR4X-4267	microSD / NVMe (via HAT)	Headless servers, IoT
Pi 4 (8GB)	8GB	LPDDR4-3200	microSD / USB SSD	Desktop use, Docker containers
Pi 4 (4GB)	4GB	LPDDR4-3200	microSD / USB SSD	Most projects, media centres
Pi 4 (2GB)	2GB	LPDDR4-3200	microSD / USB SSD	Basic projects, Pi-hole
Pi Zero 2 W	512MB	LPDDR2	microSD	IoT sensors, lightweight projects
Pi Pico	264KB	On-chip SRAM	2MB flash	Microcontroller projects

NVIDIA Jetson for AI & ML

NVIDIA Jetson boards are designed for AI inference and machine learning at the edge. They feature shared CPU/GPU memory:

Model	RAM	GPU	Use Case
Jetson Orin Nano 8GB	8GB LPDDR5	1024 CUDA cores	Entry AI development, computer vision
Jetson Orin NX 16GB	16GB LPDDR5	1024 CUDA cores	Advanced AI, robotics, edge inference
Jetson AGX Orin 64GB	64GB LPDDR5	2048 CUDA cores	Professional AI/ML, autonomous systems

Storage Options for SBCs

Since SBC RAM is fixed, optimising storage is critical for performance:

microSD cards: Cheapest but slowest. Use A2-rated cards (Samsung EVO Plus, SanDisk Extreme) for best random I/O
USB SSD boot: Raspberry Pi 4/5 can boot from USB SSDs — dramatically faster than microSD
NVMe HAT: Raspberry Pi 5 supports M.2 NVMe SSDs via official HAT — best performance option
eMMC modules: Some SBCs (ODROID, Pine64) support eMMC storage — faster than microSD, more reliable
Network boot: Pi can boot over network (PXE) — useful for clusters and centralised management

Arduino & Microcontrollers

Arduino and similar microcontrollers have very limited memory measured in kilobytes, not gigabytes:

Board	SRAM	Flash	EEPROM
Arduino Uno R4	32KB	256KB	8KB
Arduino Mega 2560	8KB	256KB	4KB
Arduino Nano Every	6KB	48KB	256 bytes
ESP32	520KB	4MB (external)	—
ESP8266	80KB	4MB (external)	—
Teensy 4.1	1MB	8MB	4KB

Recommended Products

Samsung EVO Plus 128GB microSD (A2)
Best microSD for Raspberry Pi. A2 rated for fast random read/write. Reliable and affordable.
Check Price on Amazon UK

Samsung 970 EVO Plus 250GB NVMe
Compact NVMe SSD perfect for Raspberry Pi 5 with M.2 HAT. Massive speed improvement over microSD.
Check Price on Amazon UK

SanDisk Extreme 64GB microSD (A2)
Excellent value A2 microSD for Raspberry Pi and SBC projects.
Check Price on Amazon UK

Frequently Asked Questions

Can I upgrade Raspberry Pi RAM?

No. All Raspberry Pi models have soldered LPDDR RAM that cannot be upgraded after manufacture. You must choose the RAM configuration at purchase time. The 8GB model is recommended for desktop use and Docker containers.

What is the best storage for Raspberry Pi?

For Raspberry Pi 5, an NVMe SSD via the official M.2 HAT offers the best performance. For Pi 4, a USB 3.0 SSD provides excellent speed. If using microSD, choose an A2-rated card like the Samsung EVO Plus for best random I/O performance.

Is 2GB enough for Raspberry Pi?

2GB is sufficient for headless servers (Pi-hole, Home Assistant), basic scripting, and IoT projects. For desktop use, web browsing, or running Docker containers, 4GB or 8GB is strongly recommended.

Can Arduino run out of memory?

Yes. Arduino SRAM is very limited (8KB on Mega, 32KB on Uno R4). Large arrays, strings, and complex programs can exhaust available memory, causing crashes or erratic behaviour. Use the F() macro to store strings in flash instead of SRAM.