I have never paid much attention to SD cards' write speeds as they have always been fast enough for me. Today, however, I tried recording HD video with my new Canon S100 and my old Eye-Fi Explorer card and the camera shut down the recording after 40 seconds. The camera buffer had filled up and the card was not writing the data fast enough.
I know the newest "Pro X2" is advertised as a "Class 6" card and both the "Pro" and "Pro X2" are handling HD video without problems in two other cameras, but I had no idea how much faster the "Pro X2" is compared to the old cards. With four cameras in the house and four Eye-Fi cards I did not want to buy a fifth card without having some hard facts to base my purchasing decision on.
Well, that might not be entirely true, but since I could get some hard evidence before buying, I decided to do a test.
Write speeds for the different Eye-Fi cards:
Classic: 1.8 MB/s
Explorer: 1.8 MB/s
Pro: 4.2 MB/s
Pro X2: 12.2 MB/s
The test was done with the OSX application "Blackmagic Disk Speed Test" on an iMac using the built in SD card reader. I used a 1GB test file as that is the smallest file this application can use for testing.
Read speeds are not as important and the results where all over the chart:
Read speeds for the different Eye-Fi cards:
Classic: 14.0 MB/s
Explorer: 12.5 MB/s
Pro: 18.7 MB/s
Pro X2: 15.5 MB/s
All in all, the original Eye-Fi cards are slow and the old Pro card is not very fast either. Looks like I am going to have to get myself one more Pro X2 card after all.