Extreme HD video Class10 (30Mb/s) performance

Hi,

I have a new SDHC Extreme HD Vdeo C10,

Iǘe tested it With CrystalMark 3.0 throug an USB2.0 adapter and it gives me the disapointing transfer rates of 19.8 Mb/s reading, and 6 Mb/s writing.

I understand that USB 2.0 supports a maximum of 480mbps that would be 60MB/s.

So, Is this related to UHS-I protocol?

How do I get the “about” 30Mb/s promised by the 200x rating, or even the 10Mb/s sustained writing of the Class 10 ??

Thanks

I think your weak link is the adaptor itself. In use while inserted into a compatible camera, it would be more apt to deliver the performance specified. However, when you try to “test” that through an adaptor, that in itself creates another juncture, or bottleneck that can slow it down.

you will need a hight speed reader here are a few that will give the best performance. 

http://www.sandisk.com/products/readers-accessories/sandisk-extreme-pro-express-card-adapter-for-sdhcsdxc-uhs-i-cards

http://www.sandisk.com/products/readers-accessories/sandisk-imagemate-multi-card-usb-20-reader