Class 4, Class 6, Class 10, UHS:I, U:1 - What does it actually mean for the performance of a memory card? Find out here in our tests.
Here's what 424GBs of storage looks like spread over 10 memory cards. Some of the cards have aged better than others, with some looking surprisingly aged despite being relatively new. Here is a list of all the cards we have tested, sorted with the quickest write speeds at the top. We used a USB3 card reader for testing as write and read speeds increase from 25-30MB/s up to 80-90MB/s (around 3 times quicker) compared to a USB2 reader.
In photography, write speeds are the most important as this is the speed at which a device, such as a digital camera, can write photos to the memory card. If write speeds are slow, then it may slow down your shot-to-shot time or the amount of photos you can continuously write to the card. The read speed is important for when you want to view the photos or copy them onto a computer or other device.
||Samsung PRO+ 64GB SDXC UHS:I U:3 - Review - New
||Transcend Ultimate 64GB SDXC UHS:I U:3 - Review
||integral ultima PRO X 32GB SDHC UHS:I U:3
||Sandisk Extreme Pro 95MB/s UHS:I U:1 SDHC
||Kingston 64GB SDXC UHS:I U:3 R90/W80
||PNY Elite Performance 100MB/s UHS:I U:1 SDHC
||Panasonic 64GB SDXC UHS:I U:3 R95/W90 - New
||Lexar Professional 633x 32GB SDHC UHS:I U:3
||Verbatim Premium 600x 64GB SDXC UHS:I U:1
||Sony 94MB/s UHS:I U:1 SDHC
||Sony Memory Stick Pro-HG Duo HX MagicGate 8GB*
||Fujifilm 1GB M+ XD Memory Card*
Another important factor to consider is warranty and reliability. Ideally, you would want the most reliable card possible so that your photos are never lost however, if the card does fail, then a long warranty will mean that the manufacturer should replace or repair your card. Although, recovery of images is unlikely when a card physically fails, recovery software can help recover accidentally deleted files.
Reliability can't be determined on new cards, as it could take a long time for the card to fail, if it ever does. One thing to consider is how durable the card is and if you look at Samsung cards, for example, they are waterproof, shockproof, magnetic proof and come with a 10-year warranty so should survive much more mistreatment than others, as we found out in our test of one of their microSD cards.
Looking for a MicroSD card? Have a look at the Top 10 Best MicroSD Cards.
If you're looking for a Compact Flash card, have a look at the Top 10 Best Compact Flash memory cards.
Find out more about memory cards, in our complete guide to memory cards.
* We've included XD and Sony Memory Stick memory just as a reference point, tested on a USB2 card reader, and you can see why it was a good idea for manufacturers to move away from using XD.
Updated: November 2015.