The Best SD Memory Cards For 2021

A comparison and speed tests between all the most popular memory cards and how they perform in various cameras and devices.

Fastest SD Memory Cards

This chart shows how each memory card performs with Windows 10 with Crystal Disk and a UHS-II Sandisk USB-C memory card reader. 

You can sort by speed or class to find the fastest SD memory card or the slowest. Speeds will vary slightly depending on the different readers.

Memory Card Benchmarks By Camera Brand

A list of memory card speed tests on each camera. Over the last several years I’ve been testing the most popular memory cards in each camera to find which memory cards work the best in each camera. Use this guide to find the best memory cards for your camera.

I’ve broken the list down between camera brands.

Canon Memory Card Tests

I’ve moved all the Canon tests to their own page. There are always new memory cards and it becomes difficult to test old cameras with new cards. Having a dedicated page allows me to give some general recommendations if you’re looking for new cards in an older Canon camera.

Best Memory Cards For Canon

Best Memory Card For Sony

Sony cameras until recently have been plagued by a bus speed bottleneck. Most of their cameras are only capable of write to memory cards at a speed of about 30MB/s. New cameras like the Sony A9II and the A7rIV have improved memory card performance with speeds that can even match CFexpress cards in the Nikon Z cameras.

When shooting video in Sony cameras you will not be able to use Samsung memory cards, they are not compatible.

Best Memory Card For Fujifilm

To find the best memory card for Fuji cameras, check out this guide where each camera has been benchmarked with most of the big brands of cards.

Recommended Fuji Memory Cards

Best Memory Cards For Nikon

Nikon is somewhere between Canon and Fujifilm. Some of their cameras have the 30MB/s bottleneck some don’t. This is from using older, slower UDMA tech.

Many of the pro models of Nikon cameras also use XQD memory cards which have been tested in appropriate cameras.

Best Memory Cards For Panasonic

Like many of the Sony cameras, Panasonic typically has poor memory card performance when dealing with their micro four thirds system. They have a similar 35MB/s bottleneck bus speed as Sony. The GH5 gets around this by using UHS-II memory cards that have dual lanes, so you get around 36Mb/s + 36Mb/s with a combined speed of around 70MB/s. However, the new full-frame system has incredible UHS-II and UHS-I memory card performance.

Best Memory Cards For Olympus

Some of Olympus’s older cameras have bus speed bottlenecks which restricted memory card write speeds. The new Pen-F, however, is much quicker. I still have a few more Olympus cameras to test out.

Best Memory Cards For Pentax

I haven’t tested too many Pentax cameras but the Pentax K-1 performs very similarly to the Sony A7r. It has a bus speed bottleneck so memory card write speeds are limited to about 30MB/s. 

Best Memory Cards For Ricoh

Best Memory Cards For Sigma

Sigma has a few cameras geared for a few different things, but their new L mount fp camera is loaded with some interesting specs that will make having the right memory card crucial.

Best Memory Cards For Action Cameras

The GoPro Hero 5 was notorious for having issues with memory cards. A lot of great memory cards like the Sandisk Extreme Pro just wouldn’t work properly. However, the Hero 6 and Hero 7 uses all new hardware and most of the memory card issues seen in older cameras have disappeared.

DJI Osmo Action and Osmo Pocket have had very good memory card performance even with the slightly her bitrate than what GoPro offers.

Check out this guide for the latest on the best SD cards for GoPro.

Best Micro SD Memory Cards For Drones

Every memory card I’ve tested in the DJI spark worked great. The camera on the Spark doesn’t really have great performance and it doesn’t require very fast memory card write speeds.

Best Memory Micro SD Memory Cards For SmartPhones

The Samsung Galaxy S8 and S8+ are one of the few popular smartphones to allow memory cards. I’ve tested most of the Micro SD memory cards in this smartphone to see which performs the best. The results are very surprising as performance between cards varies wildly.

Memory Card Types And Performance

What Do All The Numbers And Letters On Memory Cards Mean?

• SDHC – SDHC indicates that a card is going to use the 32-bit Fat32 file structure. This can have some performance limitations on cards. Some of the new Speed Classes like V30, V60 aren’t available on these fat32 cards. Also, you’ll see a file size limit of around 4GB.
• SDXC – SDXC indicates that the card is going to be 64-bit using the exFat file structure. This means you get all the of what technology memory cards have to offer. The V30, v60 speed classes, and larger file sizes.
• Class 10 – This is an older designation that they still put on memory cards. There used to be other classes written on memory cards, typically it would be a number inside a circle. Now every card is pretty much Class 10 and new Speed Classes have come around like U1 / U3 and V30 / V60 etc. So it’s all getting a little cluttered. Class 10 will give you a minimum guaranteed write speed of 10MB/s.
• U1 / U3 – These are speed classes like Class 10 that indicate the minimum write speed a card is capable of. U1 is 10MB/s and U3 is 30MB/s. Typically if you’re shooting high bitrate video, you’ll want the U3 cards. Some cameras like Sony’s won’t even let you use their advanced video codecs without a U3 memory card.
• V30 / V60 / V90 – This is the latest speed class. Just like Class 10 and U1 / U3, this speed class has to do with a guaranteed minimum write speeds. V30 = 30MB/s, V60 = 60MB/s and so forth.
• UHS-I / UHS-II – UHS-I and UHS-II memory cards are built completely different. UHS-II memory cards have a second set of pins that basically give the memory cards dual lanes to read and write data to and from. This makes these memory cards potentially twice as fasted when used in UHS-II devices.

Potential Memory Card Problems

Memory Card Not Working

There are several reasons a memory card may not work and I’ll list a few that I’ve seen or have personally dealt with.

1. Bad Memory Card – Every so often you can get a bad memory card, either they are DOA or they are just defective and die after a short time. Most memory card brands offer a 10-year to a lifetime warranty. Sony cards usually only offer a 1-year warranty. So you can always send your card back and try a new one. 

2. Brand Incompatibility – Some camera brands don’t like some memory cards. For example, Sony cards do not like Samsung memory cards and they will not work for video. Canon says their cameras don’t like Sony cards, although I’ve yet to have problems with Sony cards in Canon cameras, those are a few examples. If you’re having issues with a certain card in a camera, try a different brand. Sandisk cards work perfectly in most cameras.

3. Memory Card Is Slow – Again you could have a defective memory card, or, you could have a counterfeit memory card. If you bought your memory card off of eBay and you didn’t buy it from the manufacturer or trusted camera store, chances are, you could have a counterfeit memory card. Always make sure you buy your memory cards from a trusted source. BHphoto, Amazon, Adorama etc.