So how fast is it ?

For our second test we revert towards AS SSD which has an excellent sequential test option. Below the performance measured, obviously higher is better. and we measure in MB per second (not Mbit).

So we see the numbers massively increased, but sure .. reads remain below advertised performance. These transfer speeds however illustrate that once SDXC UHS-I Class 1 kicks in, you are looking at a record bandwidth that by far exceeds what any device will ever need.

Remember if you'd use a professional camera recording at 80 Mbit/sec (twice the bandwidth of Blu-ray), it would need 10 MB/sec to manage that. With this SDXC UHS-I Class 1 card you have four times the bandwidth needed for that.

Not everybody will use a storage card like this fort photo or digital camera's though. We can imagine you want to copy to and from the card media files, like 1080P MKV movie files often say 8GB in size and then use it in your media player to watch a movie or recording.

So above a very simple, file copy test. We copy a 4GB file from and towards the SD Card and that again shows seriously fast performance.

So 8 GB is transferred from the SD card to a fast client HDD/SSD in 104 seconds (1 minute and 44 seconds). Copying an 8GB movie towards the card takes (provided you use a fast enough host HDD/SSD and transfer over say USB 3.0) would take you 195 Seconds, which is 3 minutes and 15 seconds. Obviously you could also purchase  a fast USB 3.0 stick for this functionality, but we're just trying to proof a point here.