Kingston Micro SD Card

Brand Name: Kingston
Read/Write Speed: Class 10

When you test your SDC10G2 memory card, make sure that your environment is optimal, please recognize your computer's interface is USB 2.0 or USB 3.0, please check your reader or data cable is USB 2.0 or USB 3.0. (figuring manner shown as Figure 1). If your environment and hardware configuration to meet the requirements, then, KINGSTON SDC10G2 read and write speeds can be very fast. Figure 2 is a true test of our speed, we tested all the memory cards can achieve this speed. So, if you want your memory card to play its ultimate performance, please use high quality USB3.0 card reader and USB3.0  computer interface, otherwise, that will directly affect the speed of tested.

Figure 1. Understanding USB 3.0 and USB 2.0

microSDHC/SDXC Card - Class 10 UHS-I

Brand New Sealed Package
Worldwide warranty

16GB  32GB  64GB 128GB

FEATURES/BENEFITS
Compliant — with the SD Card Association specification
Versatile — when combined with the adapter, can be used as a full-size SDHC/SDXC card
Compatible — with microSDHC & microSDXC host devices; not compatible with standard microSD-enabled devices/readers; microSDXC cards are not compatible with microSDHC-enabled devices/reader

SPECIFICATION

Capacities*  16GB, 32GB, 64GB and 128GB
microSDHC/SDXC card dimensions : 0.43" x 0.59" x 0.039" (11mm x 15mm x 1mm)
Performance : Class 10 UHS-I: 10MB/s minimum data transfer rate
Operating temperature -13°F to 185°F (-25°C to 85°C)
Storage temperature -40°F to 185°F (-40°C to 85°C)
Warranty/support lifetime warranty, free technical support

About REAL Capacity

16GB     = approximately 14GB-15GB

32GB     = approximately 28GB-30GB

64GB     = approximately 58GB-60GB

128GB   = approximately 119GB-120GB

This is calculation difference between manufacturer and your PC, please Google 'Memory card capacity' to get more information.  

For your reference     

Your PC says 1GB = 1.073741824 Billion bytes where Market Defines 1 GB = 1.00 Billion bytes.

Speed of Memory card and USB    

If you feel the speed are very slow, please try to use below software to test it.  Please prepare USB 3.0 plug, USB 3.0 card reader or USB 3.0 cable before you run the test.  Otherwise, the test result will be slow as normal.

Step 1 : Download the h2testw_1.4 software in here
https://drive.google.com/folderview?id=0B-hT-W6c1ceIU3ZLMlBRV25FZlk&usp=sharing    

Step 2 : Insert your memory card / USB and follow the step in the software, it takes some time to run the test. Please make sure it will not lose connection during the test.