CPRM stands for Content Protection for Recordable Media. It is a method of copyright protection for content stored on authorized SD cards. From a technical standpoint, it uses SD-Audio and SD Binding technology to ensure duplication and/or distribution is prohibited.

Copy-protection is certainly not mandatory for all data types and can be utilized selectively at the discretion of the content owner. To use CPRM with SD cards, CPRM compliant products such as SD-Audio players, SD-Video mobile phones, or other enabled devices such as PCs with CPRM enabled SD slot or CPRM enabled USB read/write are also required.

The X speed rating gives memory device users a performance indicator on how fast the card can transfer images. Flash cards with higher X speed ratings are designed to perform faster. From a more technical standpoint, the X-speed rating indicates a megabytes (mb) per second reading speed, and represents a multiplier. A practical examples of X speed:

• If X is given as 150 kilobytes per second, then 133X = 133 times 150KB/sec = 1,000 Bytes; 1 MB = 1 million Bytes (1 kb = 1,000 mb)

Please note that speeds may vary due to host and device configuration.

Speed class is the minimum recorded speed during worst case scenario testing.

The applications standards used for speed classing are as follows:
Class 2: H.264 video recording, MPEG-4, MPEG-2 video recording
Class 4: MEPG-2 (HDTV) video recording, DSC consecutive shooting
Class 6: Mega-pixel DSC consecutive shooting, professional video camera
Class 10: Full HD video recording, HD consecutive still shooting.

The SD Association has established specifications that rate the minimum data transfer in SD, SDHC, SDXC, SDHC UHS-I and SDXC UHS-I memory cards and host products. The speed rate specifications were established based on the needs of movie and video companies. Video recording requires certain writing speeds when recording the data onto an SD card. The SD Speed Class and UHS Speed Class standardized the specification for both card and host devices in order to guarantee minimum writing speeds.

ReadyBoost is a component built into Microsoft Windows, available in versions Windows Vista and up. It uses any type of portable mass storage system (think flash memory, USB flash drive, SD card, CompactFlash, external hard drive, etc.) as a drive for disk cache in order to accelerate the system. Yes, every TwinMOS USB Flash Drive model supports ReadyBoost and is entirely compatible.

Compared to USB 3.0 with USB 2.0, USB 3.0 has a high transfer rate and stronger power supply. The highest transfer rate of USB 3.0 is 4.8 Gbps and the power supply is 900mA whereas the transfer rate of USB 2.0 is 480 Mbps and the power supply is 500mA. So, USB 3.0 transfer rate is ten times the USB 2.0 and supply stronger power. USB3.0 is backward compatible with USB 2.0. But if a USB 2.0 device is connected to a USB 3.0 port, it will only operate at USB 2.0 transfer rate.

Please follow the below steps-
1.    Please confirm the module is suitable for your computer. Cheek “Product Compatibility” section.
2.    Power off the computer and re-install the module again.
3.    Please try to change the order if more than one module is installed.
4.    Please try to install the TwinMOS module only/alone.

for your TwinMOS USB Flash Drives, we have all kinds of Application software in our web site’s Download section. Please visit for you appropriate Application software.

All storage products will display less memory capacity on a computer than stated. The discrepancy results from the different ways flash memory and hard drive manufacturers calculate megabytes. Hard drive manufacturers calculate a megabyte (or 1,000×1,000 bytes) as 1,000KBs, whereas the binary calculation is 1,024KBs. So, for a 4GB storage device, Windows will calculate it as having a capacity of 3.72GB (4,000,000,000÷1,024÷1,024÷1,024=3.72GB). So, for a 1TB storage device, Windows will calculate it as having a capacity of 931.32GB. (1,000,000,000,000÷1,024÷1,024÷1,024=931.32GB).
Furthermore, TwinMOS reserves partial memory capacity for products including firmware, software applications, and data storage maintenance. These functions include the optimization of flash memory, which greatly enhances product performance and extends service life, thus users wouldn’t be able to use this part of the capacity to store files.