It's something we often take for granted, even I've been guilty of letting this slide longer than I probably should have.
When SDHC memory cards first arrived on the scene, I splurged on a 16GB Class 4 card for my phone. It was more card than I needed at the time, as I was using an HTC Touch Pro running Windows Mobile. It carried a 3MP camera which could only muster up standard definition VGA video (640x480). Solid specs for 2008, but it barely put a dent in the new pricey memory card I'd invested in.
Then I started reviewing phones for work. That 16GB card came in handy for gadgets that supported it. Get a new phone, pop in the card, shoot some pics and vids, pull the card, and return the phone. Easy.
Of course time passed, and our gadgets got more powerful. On a recent trip down to Santa Monica, breaking in the Galaxy S5 Active, I was sorely disappointed in the camera's performance. I was testing out the UHD video, creating a simple montage video. The images were stunning, but the amount of time required to "Process" each shot was staggering. Each video took almost as long to save as it had taken to shoot in the first place.
Until I realized I'd been saving to my old Class 4 SDHC. We had finally crossed that bridge. My trusty old SD card could no longer keep pace.
Class ratings were started to help us do away with the old 'X' speed ratings, which were based on CD-ROM drive speeds. Class 4 was the bare minimum for shooting HD video, and it was a solid option for cameras that were just starting to shoot 720p. According to the SD Association, Class 4 has a read/write speed of 4 Megabytes per second. Class 4. Four Megabytes. Easy.
Phones shooting high quality HD and UHD video will routinely hit 6MB/s or more (48 Megabits per second), meaning consumers should be considering Class 6 cards at a minimum. Newer Class 10 and UHS-1 cards also utilize a new high speed bus, which allows for video to be shot and written to a card in near real time. A feature our phones now utilize.
Transcend sent us their newest 32GB "Ultimate" UHS-1 MicroSD card to test. Shooting a two minute UHD video on the Galaxy S5, the Class 4 card took over 80 seconds to save the video. Transcend's Ultimate card took less than two seconds to accomplish the same task. That also comes with the side benefit of moving data onto and off of a computer faster. Using a USB3 memory card reader, Transcend's Ultimate could read and write data at 90MB/s, well over twice as fast as my Class 4 card.
We're well through a transition. We've changed what we use our phones for, and how we use them. When Windows Mobile was my daily driver, the memory card slot was really built around the idea of passive consumption. Pack a card full of MP3s, maybe a DVD quality movie, and consume that media. Now our phones are becoming reliable content creation tools, with many consumers opting to leave traditional cameras at home. If you've been shooting high speed bursts of photos, high definition or UHD video, or large apps are slow to load, it might not be the phone struggling to perform. It might be an older memory card.
Hit the related video to see Transcend's Ultimate card in action, with real-time demonstrations of video processing and USB3 data transfers.