Best MicroSD Cards for Raspberry Pi 5: The Beginner’s Guide

✍️ Editor’s Note: All technical steps were developed, tested, and verified by the author on a real Raspberry Pi 5 deployment. This blog post was drafted with assistance from AI to streamline the writing and formatting process so that the reader may seamlessly follow along and reproduce it.

If you’re running a Raspberry Pi 5 (RPi5), the choice of MicroSD card can make or break your system’s performance. Whether you’re building a NAS, dashboard, or coding project, storage speed, reliability, and authenticity matter. This guide walks you through

• Types of MicroSD cards and what all those symbols mean
• How to choose the best MicroSD card for Raspberry Pi 5
• How to test and benchmark MicroSD card performance on Linux
• How to detect fake or dying MicroSD cards

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MicroSD Card Classes & Types

🔢 Capacity Classes

• SD: Up to 2GB
• SDHC: 2GB to 32GB
• SDXC: 32GB to 2TB

⚡ Speed Classes

Class	Minimum Write Speed	Notes
Class 10	10 MB/s	Base speed for HD video and basic OS use
U1 (UHS-I)	10 MB/s	Same as Class 10, but with UHS bus
U3 (UHS-I)	30 MB/s	Required for 4K video & fast data
V30/V60/V90	30/60/90 MB/s	Video speed classes for pro video

💡 Application Classes

Class	Random R/W IOPS	Notes
A1	1500 read / 500 write	OK for apps and OS
A2	4000 read / 2000 write	Ideal for Raspberry Pi OS, apps, DataBases

⬆️ Tip: Choose an A2 + U3/V30 card for best RPi5 performance.

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Choosing the best MicroSD card for the Raspberry Pi 5

Use Case	Recommended MicroSD Card Type
OS Boot Drive	A2 + U3 (e.g. SanDisk Extreme A2)
Backup Storage	U1 or Class 10 is sufficient
Media & File Transfer	U3 / V30 preferred
Databases / Docker	A2 mandatory for IOPS

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Benchmarking Your MicroSD Card on RPi5 (Linux)

📃 Check Device Name

lsblk

Look for your MicroSD card. Usually /dev/mmcblk0 or /dev/sdX.

⚡ Test Read Speed with hdparm

sudo hdparm -t /dev/mmcblk0

Expected for good cards: 80+ MB/s

✉️ Test Write Speed with dd

cd /media/your_mount_point
sudo dd if=/dev/zero of=./test_write bs=10M count=100 conv=fdatasync

Result will show write speed in MB/s. Clean up after:

sudo rm ./test_write

⚖️ Advanced Test with fio

sudo apt install fio
fio --name=sdtest --filename=/media/your_mount/testfio --size=1G --bs=4M --rw=readwrite --direct=1 --numjobs=1 --runtime=30s

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How to Spot a Fake or Dead MicroSD Card

🔍 Common Signs of Fake or Failing Cards

• Shows 64GB but fails to write more than 8GB
• Read-only mode triggered permanently
• lsblk shows size as 0B
• Frequent I/O errors: check with dmesg

🔧 Test for Fake Capacity

On Linux:

sudo apt install f3
cd /media/your_mount
f3write .
f3read .

On Windows:

Use H2testw to verify actual vs advertised capacity.

🔏 Read dmesg for Hardware Errors

dmesg | grep mmcblk

Look for:

• card stuck in read-only mode
• I/O error
• non-sense data

🛡️ Final Check: 0B in lsblk

If you see:

sda       8:0   1   0B  0 disk

Your card is likely beyond recovery.

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Real-World Results (Reference Table)

Card	Read Speed	Write Speed	Verdict
Lexar V30 U3 64GB	89 MB/s	30 MB/s	✅ OS-ready
Panasonic U3 16GB	73 MB/s	14 MB/s	⚠️ Backup only
KLEVV 32GB U1	49 MB/s	13 MB/s	⚠️ Backup only
SanDisk Ultra 64GB U1	86 MB/s	17 MB/s	✅ Decent for general use
(Dead) Sandisk Ultra 16GB	0B	–	❌ Discard

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Conclusion

Not all MicroSD cards are created equal — and Raspberry Pi 5’s performance is highly sensitive to MicroSD card quality.

✅ Recommended: Best MicroSD card for Raspberry Pi 5

• A2 + U3 or V30 cards (e.g. SanDisk Extreme A2, Samsung Pro Plus)
• Regular testing every 1–2 months for active OS cards
• Use f3 or H2testw to verify capacity

A highly recommended option: Raspberry Pi’s Official MicroSD Card. It ticks all the right boxes at an affordable price point. Tom’s Hardware has some good alternate recommendations as well: Best microSD Cards for Raspberry Pi 2025

❌ Avoid:

• Generic or unlabelled MicroSD cards
• Cards showing 0B in lsblk
• Any card that randomly enters read-only mode

Don’t let your MicroSD card be the cause of your RPi5 deployment’s weakest link!