Help! Is a TF card or microSD card required for my device? What IS the difference?

When it comes to memory cards, the market offers a plethora of options aimed at various devices. TF cards and microSD cards are two of the most well-known of these options. These cards are used as primary or secondary storage devices in a wide range of devices.

Having said that, there is some misunderstanding about what a TF card is. Is there a distinction between a TF card and a microSD card? Is it the same thing? Which one should I choose?

What Is a TF Card?

In 2004, Motorola and SanDisk introduced TransFlash (TF) cards as a replacement for SD cards. Secure Digital cards (SD cards), as you know, are memory cards used in digital cameras and other devices which require portable storage. Although SD cards are the most widely used storage format, they are larger and more cumbersome than a TF card.

TF cards were designed to be smaller and more compact than SD cards while still retaining SD card functionality. This means you can use a TF memory card in your digital camera or any other device that accepts an SD card with the help of an SD card adapter.

What is a MicroSD Card?

MicroSD cards are simply rebranded TF cards. When Motorola and SanDisk released the TF card in 2004, it was released as a separate standalone product. Aside from the fact that TF cards supported the same standard specifications as SD cards (except for the size), they were a distinct, non-standardized product class.

The SD Association, which is the governing body over the Secure Digital specifications and compliance guidelines, adopted TF cards as microSD cards to standardize these flash memory cards.

So, microSD cards are TF cards in disguise.

TF Card vs. microSD Card: What’s the Difference?

There are no distinctions between TF cards and microSD cards. Both can be used interchangeably. For example, if you have a TF card but your smartphone only supports microSD cards, you can use your TF card. It will work perfectly because it adheres to the same standard.

Which Card to Pick Up?

If you need a memory card for your digital camera or older gadgets but don’t need one for your smartphone, a full-sized SD card is the way to go.

On the contrary, if you need a card for your smartphone alone, you have no other option than a microSD card.

Finally, get a microSD card with an SD adapter so that you can use your card in both your smartphone and other devices. Because MicroSD cards use the same standard interface as SD cards, they can be used in place of SD cards with the help of an SD card adapter.

SD Card Duplicator UPDATE:

The Drive Manager software which powers this SD Card Duplicator now offers the ability to write CID values to the SD cards. The CID (Card Identification) of a Secure Digital (SD) card is a unique identifier embedded within the card’s read-only memory by the manufacturer. It serves as a distinct serial number for the card and typically consists of specific information such as the card’s manufacturing date, manufacturer ID, and other proprietary data.

The CID number is accessed through a hardware chip and vendor command on a compatible host system, such as an SD card reader or a specialized device like the SD160PC SD Card Duplicator mentioned here. This unique identifier can be valuable for various purposes, including device authentication, data encryption, and tracking of individual SD cards within a system.

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Continued…

You’ve heard the quote “the devil is in the details” and when it comes to duplication of data to SD cards, nothing can be more true. Today we talk about an SD Card Duplicator which provides the ability to data stream unique content to each card.

Typically a user would duplicate the same content to SD cards because they intend to make many copies of the same content. However, many companies who use SD media (or microSD media) want to not only copy the same content to each card, but also copy unique data to each card.

Let us dig a little deeper with an example:

It is very common for companies who generate map data also want to protect their mapping information. Maps are expensive to make and often hold proprietary information that companies want to protect. So when it comes time to use an SD Card Duplicator to make hundreds or thousands of copies, it is required to have a protection scheme included with the duplication solution.

A common method to provide protection on SD card media is using the CID number of the card. The CID number is a value which is put into read-only memory of an SD card and that CID number is unique to each card and follows the card around. It is not possible to copy or duplicate the CID number—it is a value which is designed to only be read. In addition to the unique number, it requires specific vendor commands to read the CID number from the card itself.

With an SD Card Duplicator from Nexcopy it is possible to read the CID number because Nexcopy uses the special vendor commands to read the CID value.

So this is what a mapping company can do with an SD Card Duplicator:

• Encrypt the mapping data
• Include a text file with the decryption code for the maps
• Include the CID number of the physical card in the text file mentioned above
• Since CID numbers are unique to each card, write the unique key code text file to each card

With the SD Card Duplicator the user can export the CID numbers in bulk during the duplication process. When the CID numbers are exported in bulk, the company can write a script to generate key code text files which can only be decrypted by the card which holds the correct CID value.

The final step of the SD Card Duplicator would be writing the encrypted map data to all the SD cards (or microSD cards) and make a second duplication pass to perform the unique data stream of the encrypted file which holds the CID number and key code to each individual card.

There are certainly some custom scripts or batch files which the end-user would need to write, but the bulk of the duplicator process would be done by the Nexcopy SD Card Duplicator.

Secure Digital (SD) is a proprietary non-volatile memory card format created by the SD Association (SDA) for use in portable devices.

The standard was introduced in August 1999 as an improvement over MultiMediaCards (MMCs) by a collaboration of SanDisk, Panasonic (Matsushita), and Toshiba, and has since become the industry standard.

In January 2000, the companies also established the SD Association (SDA), a non-profit organization, to promote and develop SD Card standards.

SanDisk Launches Extreme Pro microSDHC UHS-I Cards With 90MB/s Write Speeds

SanDisk is launching two new microSD memory cards today, officially called the SanDisk Extreme Pro microSDHC UHS-I cards. What makes them special? They allow you to capture photos and videos at up to 90 megabytes per second, which is incredibly fast for any application. As for read speeds, they’re slightly faster at 95 MB/s. That’s nowhere near maxing out a USB 3.0 connection (625 MB/s), but still an impressive figure for microSD media.

The 8GB version will retail for $60, while the 16GB model is priced at $100. Both will be available in stores soon, and for those who can’t wait, they can be purchased directly from SanDisk’s website today.

With write speeds reaching 90MB/s and read speeds at 95MB/s, the SanDisk Extreme Pro microSDHC UHS-I cards set a new benchmark for performance in small-form storage.

What “UHS-I” Actually Means

UHS-I is the first generation of the Ultra High Speed bus used by SD and microSD media. On paper it supports bus speeds up to 104 MB/s (SDR104). That’s the ceiling for the interface itself; real-world read/write numbers depend on the card’s controller, NAND quality, and the host device’s slot. In practice, a 90 MB/s write / 95 MB/s read Extreme Pro microSDHC UHS-I card sits near the top of what UHS-I can deliver, which is why these cards feel snappy for continuous photo bursts and high-bitrate 1080p/4K recording—provided your camera or phone can keep up.

Speed logos matter: “UHS-I” (the Roman numeral “I”) is the bus type; “U1” or “U3” indicate minimum sustained write speeds (10 MB/s or 30 MB/s, respectively); and “V30/V60/V90” video classes target continuous capture needs. When in doubt, match the card’s bus and speed class to the device manufacturer’s recommendations rather than chasing the highest spec on the shelf.

Where These Cards Shine

Cards at this performance tier are a strong fit for mirrorless cameras shooting 1080p/4K, action cams, drones, and gaming handhelds that benefit from fast level loads. They’re also practical for Android devices that support adoptable storage—fast random performance keeps apps feeling responsive. If your workflow includes frequent file offloads, pair the card with a UHS-I reader on a USB 3.x port to avoid a host-side bottleneck.

About SanDisk (and Today’s Ownership)

SanDisk has been one of the foundational brands in flash storage since the late 1980s, building everything from memory cards to SSDs and professional media. In 2016, SanDisk became part of Western Digital, which combined its HDD expertise with SanDisk’s flash technology. The brand you see on retail shelves is SanDisk; the public company behind it is Western Digital.

Stock Snapshot (for context)

As of September 22, 2025, Western Digital’s ticker is NASDAQ: WDC. The latest quoted price during today’s session is $112.41. Prices move throughout the day, so treat this as a point-in-time snapshot rather than investment advice.

How to Read and Write CID Values on SD and microSD Media

UPDATE (Feb 16, 2023): The company that manufactures this product now offers the ability to write the CID value as well as write protect the Secure Digital media.

GetUSB.info recently published an article on how to read the CID (or PSN) from an SD card, also known as the product serial number. Some call this simply reading the CID number from an SD card. The CID number is a unique identifier created on the SD or microSD card at the time of manufacturing. It cannot be changed or manipulated by the host computer.

The CID number is most often used by vendors or manufacturers to lock software to a specific device. Because the CID number cannot be altered, it serves as a secure way to prevent unauthorized distribution of software or content.

Some manufacturers require reading the CID number from SD media before releasing software, and this is what GetUSB.info explains in detail. For a full description, see the article: How to read CID number from SD media.

Here is a snapshot of the CID reading tool for 20 SD devices:

The CID number is composed of the following values:

1. Manufacturer ID: An 8-bit code that identifies the manufacturer of the SD card.
2. OEM/Application ID: A 16-bit code that identifies the OEM or the application for which the SD card was designed.
3. Product Name: A 32-bit ASCII code that specifies the product name of the SD card.
4. Product Revision: An 8-bit code that specifies the product revision of the SD card.
5. Serial Number: A 32-bit code that specifies the unique serial number of the SD card.
6. Manufacturing Date: A 12-bit code that specifies the manufacturing date of the SD card.
7. CRC: A 7-bit code used to verify the integrity of the CID number.

The CID number is typically used by SD card host devices to verify authenticity and ensure compatibility with the host system.

Nexcopy Inc., based in Southern California, specializes in developing and manufacturing USB duplicators, SD card duplicators, and other digital media equipment. Founded in 2008, the company has built a reputation for high-quality, reliable solutions used across education, government, military, and commercial sectors.

Nexcopy’s products are recognized for their speed, reliability, and ease of use. For example, its USB duplicators can copy up to 60 drives simultaneously at transfer speeds of up to 33 MB/s per port. Its SD card duplicators can handle up to 40 SD cards at once with speeds reaching 90 MB/s per port.

In addition to hardware, Nexcopy provides software solutions for USB and SD duplication and offers custom programming for clients with specialized requirements.

Overall, Nexcopy remains a trusted leader in the digital media duplication industry, known for reliable products and strong customer support.