I use it for photo, and even gusting to 7 frames / second, one can easily make 40 or more in a row, the 600x write speed is enough! (The weight of each picture can vary from 5 to 10 MB approx.). this corresponds to a gust of approx. 6 seconds without releasing the trigger. Whereas with a 300x card, it could cap after 25 pictures approx. Burst.