Not all microSD cards are equal, and the marketing numbers on the packaging rarely match real-world results. I’ve run 35 cards through sequential and random read/write benchmarks to find out what actually performs for action cameras, drones, handheld consoles, and photography. Here’s what the data shows.
The Fastest MicroSD Right Now
The table below is sorted by sequential write speed — the number that actually matters for recording video. Sequential write determines whether a card can sustain the data rate your camera or action camera needs without dropping frames or throwing an error mid-clip. Read speed is largely irrelevant for recording; it only comes into play when transferring footage off the card.
A note on UHS-II cards: I’ve excluded them from this list — their main value is transfer speed when offloading footage to a computer, not for in-device recording. The Lexar 1800x hits 290 MB/s write speed, but only with a UHS-II card reader. No current action cameras or drones have UHS-II hardware, so in-device speeds are capped at UHS-I regardless of the card. The fastest UHS-I card in my tests, the Samsung Pro Ultimate V30 A2, wrote at 179 MB/s — fast enough for everything these devices can shoot. If you regularly offload large amounts of footage, a UHS-II card and reader are worth it for the speed. Otherwise, the Samsung is the practical pick.
MicroSD Memory Card Benchmarks
How I Test
Sequential benchmarks were run using AJA System Test on a Windows 11 machine with a ProGrade USB-C 10 Gbps card reader. I use a 5120×2700 5K Red 16-bit RGBA file target — the same format AJA uses for high-end video production workflows — which delivers consistent, repeatable results without being inflated by small file sizes.
Random read and write speeds were tested separately on a Retroid Pocket 5 running Android 13, since it exposes the full range of IOPS data in a way most desktop tools don’t. This matters specifically for handheld console performance, where random read speed affects load times more than sequential throughput.
A note on capacity: most cards in this test are 128GB. Some manufacturers bin their NAND differently across capacities, meaning a 64GB and 256GB version of the same card can have meaningfully different write speeds. Where I’ve seen that in the data, I’ve broken those out separately. If you’re buying a different size than what I tested, check the spec sheet — the rated write speed on the packaging is the number to compare.
Every card was tested cold, formatted fresh, and run through at least three passes before recording results.
Best for Action Cameras and Drones
For action cameras and drones, sequential write speed matters — specifically, sustained sequential write speed, not burst. Video data is written to the card continuously in large blocks, so random read/write performance and IOPS are largely irrelevant here.
What You Actually Want
What you actually want is V30 (U3), which guarantees 30 MB/s sustained write. That’s the real-world ceiling for action cameras and drones, and it’s enough to handle 4K at the bitrates these devices shoot at. Anything rated V30/U3 from a reputable brand will do the job.
From my tests, the SanDisk Extreme Pro or Plus is the strongest performer in this category — with a sequential write speed of 173 MB/s, consistent across multiple passes without throttling. The Sandisk Extreme is the budget pick that still clears V30 reliably at SEQ WRITE of 96 MB/s
One thing that matters more for this use case than card readers or cameras is durability. MicroSD cards in drones and action cameras take more physical abuse — from drops, water and temperature swings. All the cards I’d recommend here are rated for at least -25°C to 85°C and IP67 water resistance. Check that spec if you’re shooting in rough conditions.
What Not To Buy
Every action camera and drone on the market today uses a UHS-I slot. That’s an important point because it means V60 and V90 speed-class ratings are effectively irrelevant for these devices — those speeds require UHS-II hardware, and none of these cameras have it. A V60 UHS-II card will work in a GoPro or DJI drone, but it’ll run at UHS-I speeds. You’re paying for a performance the device can’t use.
MicroSD Express: For Nintendo Switch 2
The Nintendo Switch 2 requires MicroSD Express cards. Standard microSD cards — including fast UHS-I and UHS-II options — are not compatible. This isn’t a marketing footnote; the Switch 2 uses the PCIe/NVMe interface that MicroSD Express runs on, which is fundamentally different from the older UHS bus.
MicroSD Express cards look identical to standard microSD cards but have a small notch on the back contact edge. The speed difference is significant — conventional microSD tops out around 300 MB/s in the best cases, while MicroSD Express can reach 800 MB/s or more on compatible hardware.
One thing to keep in mind: MicroSD Express cards work in standard microSD slots as a fallback — they’ll function at regular microSD speeds in older devices. So if you’re buying the Switch 2, you won’t brick anything by putting it into another device while you wait for your console.
Memory Card Ratings and Number: Speed Classes Explained
Understanding all the numbers, letters, and ratings on memory cards can be daunting. To make it easier, here is an overview of what you need to know about memory card ratings and terminology. With this information, shopping for memory cards will be a breeze!
EX
EX stands for Express, a new microSD card that offers significantly faster read and write speeds, making it ideal for console gamers on the Nintendo Switch 2.
A1 vs A2
A1 and A2 memory cards are among the latest and most advanced in terms of random read and write speeds. Both offer exceptional storage expansion options and support specific applications. However, there are some differences between them that you should consider when deciding which is best for your needs.
A1
A1 memory cards were the first standard for improving random read and write speeds. They are guaranteed to achieve a minimum performance of 1500 IOPS for random reads, 500 IOPS for random writes, and an absolute minimum of 10 MB/s for data writes or copies.
A2
A2 Memory cards feature a data caching system that is ideal for applications with intensive random read and write operations. With a minimum random read speed of 4000 IOPS, a minimum random write speed of 2000 IOPS, and a sustained write speed of 10MB/s, these cards provide superior performance compared to other cards on the market.
What are IOPS?
What are IOPS? IOPs stand for Input/Output Operations Per Second and measure the speed and efficiency with which a storage device can access data. The higher the IOPS rating, the faster a storage device can read and write small chunks of data, thus allowing applications to run more smoothly. When purchasing a storage card or hard drive, consider its IOPS to ensure optimal performance.
How do Micro SD Cards Compare to SSD drives?
When comparing the performance of a microSD card to that of an SSD, it is clear that the latter offers much faster performance. For instance, the Samsung 850 PRO can achieve up to 100,000 IOPS (Input/Output Operations Per Second). Even with higher-end models, its IOPS count can reach 500,000; by comparison, a micro SD card can only handle 4,000 IOPS. Those seeking more advanced work on their mobile devices will benefit more from using an external SSD rather than a microSD card.
U1 / U3 / V30 / V60 / V90
Memory cards are grouped into classes to indicate their guaranteed minimum write speeds. A U1 rating stands for a data transfer rate of 10 megabytes per second (MB/s), U3 is 30 MB/s, V30 is 30 MB/s, V60 provides 60 MB/s, and V90 is the highest at 90 MB/s. Older memory cards can be identified by looking for a circled 10 on the card; these cards have a write rate similar to that of a U1 card, at 10 MB/s.
UHS-I vs UHS-II
UHS-I and UHS-II are two types of high-performance microSD cards with distinct features. UHS-I cards are more widely used in smartphones, tablets, and other devices due to their widespread accessibility across various devices. However, UHS-II memory cards offer higher speeds by adding a second data lane and an additional row of pins. This can significantly improve read/write speeds and IOPS, making these an ideal choice with cameras and high-bitrate video formats.
Best Micro SD Memory Card Conclusion
When choosing the best micro SD memory card, it’s important to consider speed, capacity, and compatibility. For most users, a high-speed UHS-I card with good performance and adequate storage should be plenty. However, if you need even faster read/write speeds and have a compatible device, UHS-II cards are your best bet. The best microSD memory card will depend on your individual needs, budget and your device’s compatibility.
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