To test the speeds of the Micro SD cards here, we used a Lexar USB 3.0 Micro SD card reader with a compatible USB 3.0 computer. We transferred 1GB of information using a program called H2testw1.4. This calculates the read/write speed in MB/s and also how many seconds the reading/writing took per 1GB of information. Each card was tested twice and we took the highest score for each.

Lexar High-Performance microSDHC UHS-I (633x)

Price: £60 (32G)
Read 67.6-71.1MB/s (14secs) Write 18.9-19.6MB/s (51secs)

Lexar says it has designed the High-Performance microSDHC UHS-I (633x) card with action sports cameras in mind, as well as tablets, smartphones and stills cameras. This is why this card focuses heavily on high speed and can, according to Lexar, capture and play back 1080 full HD at 24fps, 3D and 4K video. I found the write speed to be 19.6MB/s, while the read speed was the highest on test at 71.1MB/s.

This card will also be available in 16GB and 64GB versions. Included with the card is a USB 3.0 Micro SD card reader, which is very fast at transferring files and, ultimately, a very useful piece of kit to have.

Lexar High-Speed MicroSDHC

Price: £15 (8GB)
Read 18.7-19.3 MB/s (51secs) Write 15.3MB/s (1min 45secs)

Like the other Lexar card on test, the High-Speed MicroSDHC also has a Micro SD card reader included. However, this is a slower USB 2.0 version rather than the USB 3.0 reader that comes with the High-Performance card. As the High-Speed MicroSDHC card is the older model, its price has dropped, making it very affordable.

In addition to the 8GB version, a 16GB card can be bought for around £19, and a 32GB for can be bought for around £34. With a write speed of 15.3MB/s, this card is quick enough to suit most shooting situations, although it does have the lowest read speed on test of 18.7MB/s.

Samsung MicroSDHC Pro UHS-I

Price: £12.50 (8GB)
Read 54.3-54.4MB/s (18secs) Write 19.3-19.4MB/s (51secs)

Samsung says its development of memory cards is focused primarily on the reliability of the memory card and the preservation of the data stored on it. As well as technology advancements that reduce the risk of data corruption, Samsung has made sure that many of its Micro SD cards are waterproof, temperature-proof, X-ray-proof and magnet-proof. However, this hasn’t resulted in a huge trade-off in speed. In fact, the write speed of the Samsung card is not far behind that of the Lexar High-Performance card (left) at 19.3MB/s.

In addition, the Samsung card features a read speed of 54.4MB/s. A range of cards for 2014, due to be released soon, are promised to be even faster while retaining the class-leading reliability.

Leef Pro MicroSD 16GB

Price: $24.99 (around £15)
Read 37.9-38MB/s (26secs) Write 11.4-11.6MB/s (1min 27secs)

Leef is a little-known company that specialises in making high-quality flash-memory products. Sitting alongside its standard MicroSD card is the Pro MicroSD. This is a stylish-looking card that is available in capacities of 16GB, 36GB ($44.99/£27.50) and 64GB ($84.99/£52). The memory is die-sealed into thermoplastic, which makes the cards waterproof and shock-resistant.

Included in the kit is an equally well-styled Micro SD to SD card adapter and a plastic case to prevent damage during transit. When tested transferring a 1GB file between a PC and the card, the Leef Pro MicroSD achieves a write speed of 11.6MB/s and a read speed of 38MB/s. The results are a close match for the Sony card, and the Leef Pro card achieves an equally high performance.


Price: £11 (8GB)
Read 39MB/s (25secs ) Write 10.1-10.2MB/s (1min 37secs)

Surprisingly, the Sony SR-16UYA (16GB) on test had the slowest write speed of all the cards here. At just 10.1MB/s, it took 1min 37secs to write a 1GB file to the card. The read speed was a respectable 39MB/s. However, I found these speeds were sufficient to capture 1920×1080-pixel, full HD footage at 30fps without any dropped frames and, like all the other cards, it is more than capable of continuous shooting of raw and JPEG images combined.

Included with the Sony SR-16UYA card is a Micro SD to SD adapter, which is very useful as many card readers don’t have a Micro SD slot. Like the SanDisk card (left), recovery software is included in the form of Sony’s File Rescue. Available in 8GB, 16GB (£20), 32GB (£39) and 64GB (£49), this card offers great value for money.

SanDisk Extreme microSDHC/SDXC UHS-I

Price: £25 (16GB)
Read 68.2MB/s (1GB: 14secs) Write 26.9MB/s (1GB: 37secs)

The SanDisk Extreme microSDHC/SDXC memory card is available in capacities of 16GB, 32GB or 64GB. We tested the 16GB version and found it to have a write speed of 26.9MB/s when transferring a 1GB file from a computer to the card using a USB 3.0 card reader. This is the fastest speed of any of the cards on test, and when used in a camera I found it was fast enough to record full HD video at a resolution of 1920×1080 pixels at 60fps, and possibly higher resolutions depending on the camera’s level of compression. The read speed was second fastest on test at 68.2MB/s.

In addition to the class-leading speed, the SanDisk Extreme card is waterproof, X-ray-proof, temperature-proof and shock-proof, making it very durable. Furthermore, SanDisk Rescue Pro Deluxe software, which is used to recover lost or corrupted files, comes free with the card.