Everything you need to know about SD memory cards

5 SDXC cards tested for 4K recording and burst shooting

We tested these cards’ read/write speeds for both images and video, recording overall transfer times and read/write fluctuations which could result in dropped video frames. All these cards are UHS-I types, with a single row of contacts on the back. UHS-II SD cards have a second row of contacts, offering up to three times the theoretical speed, though you need a compatible camera.

1. SanDisk Extreme Pro 64GB

SanDisk’s contender produced a blistering 83.3MB/s video write rate, and it wrote images at a sustained 56.4MB/s with no speed dips, making it the smoothest performer here.

2. Samsung Pro+ 64GB

The Pro+ turned in the fastest outright image write rate of 58.2MB/s, but not without some minor speed fluctuations. Read performance is faultless, however, as is video write speed.

3. Kingston SDXC UHS-I U3 64GB

Kingston’s fastest SD card managed a whopping 84.1MB/s when writing video, though transferring multiple image files resulted in a mediocre 42.8MB/s, with lots of speed fluctuations.

4. Transcend SDXC UHS-I U3 64GB

Despite sharing the same speed class ratings as SanDisk’s entry, this card only managed an erratic 36.8MB/s average image write speed. 64MB/s when writing video isn’t too shabby, though.

5. Lexar Professional 633x SDXC UHS-I 64GB

It may only have a UHS Class 1 speed rating, but this card’s read rates are a match for the competition. Write speeds of 53MB/s with video and 36.7MB/s with images trail the pack, though.

Alternatively, you could get a microSD card

Samsung Evo Plus

If you want to invest in a card that you can use across a number of devices, you might want to look at a microSD card like Samsung's new Evo Plus range. Coming complete with a full-size SD card adapter, the cards feature the brand's NAND technology with read speeds at 100MB/s and write speeds as quick as 90MB/s. As well as this, the card is waterproof, freezeproof, X-Ray proof and magnetic proof.