Which SD card is best for a Raspberry Pi?

While you can boot a Raspberry Pi from a USB SSD or an M.2 SSD, most people still use a plain vanilla SD card.

An SD card is a very good choice for most applications, and a digital picture frame is no exception.

Even the latest Raspberry Pi 5 does not support the speeds of high-end SD cards, so paying for a faster model yields no benefit beyond a certain point.

However, I noticed significant performance differences between certain SD cards. That led me to run a quick test to determine the optimal choice for my setup.

This article won’t dive too deep into technical details—other blogs cover that well. But if you’re wondering which SD card is best for your digital picture frame, you’ve come to the right place.

The test setup

This is not a comparison across brands but a test of two SanDisk models: the SanDisk Extreme and the SanDisk Extreme Pro. I chose SanDisk because they have a reputation for reliability and performance. Samsung offers comparable models, and I expect similar results.

I conducted the test on both a Raspberry Pi 4 and a Raspberry Pi 5, which highlighted the performance improvements in the newer hardware.

Using a freshly installed SD card, I ran the fio (Flexible I/O Tester) package—a powerful benchmarking tool that simulates various read and write workloads.

As a real-world reference, fio suggests the following typical storage speeds for a Raspberry Pi:

• Cheap SD card: 10-20 MB/s
• High-speed SD card (A2, UHS-I): 30-90 MB/s
• USB 3.0 SSD (on Pi 4/5): 100-400 MB/s (depending on the SSD and adapter)

I performed sequential read and write tests on both the Raspberry Pi 4 and Pi 5, first using the SanDisk Extreme and then the SanDisk Extreme Pro.

Results:

On a Raspberry Pi 4, there was no difference using the alleged faster Pro card.

However, on a Raspberry Pi 5, the SanDisk Extreme was 44% faster in writing and more than twice as fast when reading than on a Pi 4 model.

The difference of a SanDisk Extreme Pro card on a Pi 5 was only sensible in the Write Speed, I got the exact same read speed.

SanDisk advertises speeds of up to 200 MB/s for reading and 90 MB/s for writing on the Extreme Pro packaging. Clearly, there’s still room for improvement on the Raspberry Pi side regarding interface performance.

In doubt, buy a bigger SD card

Storage media have a limited lifespan as memory clusters degrade over time. A larger SD card means more unused space, reducing wear on individual clusters and extending the card’s lifespan.

Given how cheap storage has become, I recommend buying at least a 64GB card—or better yet, a 128GB card—as the price difference is usually minimal.

Which one to buy?

If you use a Raspberry Pi 4, the SanDisk Extreme is as good as possible. However, since the price gap to the Extreme Pro is small, I suggest opting for the Pro version unless you are on a very tight budget. In either case, make sure you buy an A2-rated card.

What about Endurance cards?

Some manufacturers offer SD cards designed for continuous read/write operations, such as surveillance cameras. However, they don’t specify how much more reliable these cards are, and no guarantees are provided.

I typically replace the SD card in my digital picture frame every two to three years. I probably don’t need to, as card quality has improved over time, but I do it as preventive maintenance. It often coincides with a major Raspberry Pi OS upgrade, like the transition from Buster to Bookworm.

I’ve used both Endurance and standard SD cards and have not noticed any reliability differences. The price premium for Endurance models may not be worth it—you might be better off buying a larger card.

Conclusion

For a digital picture frame, I recommend the SanDisk Extreme Pro 128GB, whether you’re using a Raspberry Pi 4 or 5. The price difference is small, and a reliable SD card can spare you a lot of headaches.

That peace of mind is priceless.

Thank you for your support and motivation.