Having just upgraded my dashcam to a dual channel affair, I thought I'd increase the size of my Micro SD card to allow for the extra footage from the second camera. The camera I purchased was the Vantrue N2 Pro. It records at these resolutions: 2560x1440 @30fps front only 1296p @30fps front only 1080p @30fps both cameras 1080p @60fps front only I figured 5 min clips at 1440p would be about a gigabyte with 1080p being half of that. I wasn't that far off to be fair (990 odd Mb for 1440p, 485Mb for 1080p). Anyway, my previous 32gb card just wasn't going to cut it so I started browsing Amazon for a 64 or 128 and found a SanDisk Ultra 128gb Class 10 for £23. Bargain or so I thought... The card arrives, formats it and off we go for a test drive. Records OK, all files present but when I get them off the card onto the PC, the video is stuttering like mad. Thinking I'd bought a duff camera, I went through various forums, settings on the camera, tried recording again with g-sensor off, GPS off, audio off - no dice. So I started thinking about the SD card but surely it's fast enough? It's a SanDisk Ultra Class 10! 85Mb/s - says so on the box! Well a quick test or two later, read is indeed 85Mb/s but the write speed (which is the only one that matters for dashcams/cameras etc) tested at 27Mb/s. Now, and here's the rub... 27Mb/s is enough to record 1440p video nearly 9 times over; however, after a bit more internet searching, the SanDisk controller just isn't fast enough to process the constant writes from the dashcam. There are lots of accounts of this with SanDisk (and other well known brand) cards. I've now got a 128gb Samsung Evo Pro card on the way, for £1 more than the SanDisk, which I've been recommended by another Vantrue owner who had similar issues. It reads at just short of 95Mb/s but crucially it writes at just over 70Mb/s despite being the same Class 10 as the SanDisk but therein lies the cautionary tale.