Do you wonder How do SD cards work?

In this article, will uncover the workings of SD cards, which are widely used storage devices compatible with various devices such as laptops, cameras, phones, game consoles, and even cars. We will cover the fundamental principles of SD cards, including their technology, data storage and retrieval, and proper usage.

On the other hand, we will address typical issues encountered with SD cards, such as corruption and write protection, and provide solutions to tackle them.


 SD Memory Card. What is It?

The SD Memory (Secure Digital) card is a highly popular storage device due to its small size, large memory capacity, fast data transfer speed, and reliable security. Being a type of flash memory, it can endure thousands of writes and retains its contents without needing power. As a result, it’s widely used on various devices, from computers to phones, cameras, and even cars.

Another advantage of SD cards is that they have no moving parts, making them more robust and capable of withstanding accidental impacts. However, it’s important to note that not all devices are compatible with SD cards. Although some electronic gadgets like phones and cameras have an SD slot, they may be configured not to accept SD cards. As for computers, many come with built-in memory card slots for SD and other memory cards. But if your computer doesn’t have one, you can easily purchase a USB memory card reader to enable the use of an SD card.

micro SD card adapter


SD Memory Cards. How Do They Work?

Despite the familiarity with SD cards, many are unaware of how they function in electronic devices such as phones. So, how do SD cards work? The answer is as follows.

SD cards utilize NAND chips, which are electronic components of flash memory, to store digital files. NAND chips enable data to be written and stored on the SD card without the need for a power supply. With no moving parts, data transfer from SD cards is rapid. In fact, the data transfer speeds on SD cards exceed those on other storage devices, such as CDs or hard drives.

When data is written to an SD card, it is initially stored in a buffer memory. Subsequently, the data is recorded in blocks of data and stored in the appropriate memory cells, which are arranged into pages. Every page comprises a specific number of data bytes along with additional bytes for error correction and control information.

When data is read from an SD card, the controller reads the data from the relevant memory cells and transfers it to the requesting device. Additionally, the controller may execute error correction and other operations to maintain data integrity.

As NAND chips are highly robust, SD cards can be written to thousands of times throughout their lifespan without wearing out easily.

SD cards have diverse formats. Learn the difference between SDHC and SDXC SD cards >>>

SD Card Speed Class

SD card speed is a crucial consideration for users. The speed class rating of an SD card indicates its minimum write speed, i.e., the rate at which it can write data to the card. A higher speed class rating implies that the card has a faster writing capability.

SD cards typically have one of three different speed class ratings: Speed Class, UHS Speed Class, and Video Speed Class. Each rating represents the minimum write speed of an SD card and can assist in selecting the appropriate card for specific needs.

Read the following article to learn more: SD Card Speed Classes (How to Choose Guide).


What is a Write Protection?

Certain SD cards feature a “lock” mechanism to prevent inadvertent loss of data. This is accomplished through a small switch that, when activated, prohibits the card from accepting new data or overwriting existing data. Furthermore, it’s simple to remove write protection from an SD card.

Typically, the write protection switch is found on the side of the SD card, near the brand name or label. It can be toggled between the lock and unlock positions by sliding it back and forth. In the locked position, the card is write-protected and can’t be modified, formatted, or written to until the switch is moved to the unlock position.

This feature is especially useful for handling sensitive data or using the SD card to store critical files. It adds an extra layer of protection against accidental deletion or corruption, assuring the user that their data is secure.

Learn how to unlock your SD card from the write protection>>>

write protection

How Can You Use SD Memory Cards?

Below are the steps to utilize SD cards on different electronic devices:

Using an SD Card on a Computer:

  1. Insert the SD card into the card slot on your computer.
  2. Open File Explorer and locate the SD card under Devices and Drives. It is typically identified by its brand name and assigned a drive letter.
  3. Double-click on the drive to access and manage the files on the SD card or transfer data between the card and the computer.
  4. When finished using the SD card, it is important to safely remove it from the computer to prevent data loss or card corruption. To do this, right-click on the drive and select Eject.

If your SD card is corrupted or damaged, refer to this article for quick and easy solutions.

Here are the instructions for using SD cards on a camera:

  1. Format the SD card before first-time usage. Check out the following article to know how to format your SD card: How To Format micro SD Card Using Computer or Mobile. It is possible to format the card on a computer, it is recommended to format it on the camera for full compatibility with the camera’s file type.
  2. Turn off the camera and insert the SD card into the card slot.
  3. Turn on the camera and navigate to the Menu or Preferences option.
  4. Find and select the Format option.
  5. Confirm that you want to format the SD card and wait for the process to complete.

After formatting the SD card, it’s ready to use with your camera. You can begin capturing your favorite shots and store them on the SD card.

Using an SD Card on a Phone:

In today’s smartphones, SD card slots are not as common as they once were. Phone manufacturers have increased the internal memory of their devices significantly. However, if you have an older phone with an SD card tray, using an SD card is a breeze. Simply insert the SD card into the slot and follow the on-screen instructions to set it up.

On some Android phones, you can even use the SD card as internal storage.

If you find that your SD card is corrupted you can fix it inside your Android phone, just follow the instructions given in the article: Fix Corrupted SD Card on Android Step-by-Step [Without PC].

What is a price for an SD card? Read the following article to know the updated priced of the most popular SD cards.


What Should Be The Suitable Storage Capacity for My SD Card?

The appropriate GB capacity for your SD card relies on various factors such as the frame rate, resolution, and bitrate of the videos you intend to record. Typically, a 32GB or 64GB SD card is adequate for video cameras that shoot in 1080p or Full HD. However, for shooting in 4K or higher resolutions, it’s preferable to opt for a larger capacity SD card, such as 128GB or 256GB, to accommodate the larger file sizes.

Consider the bitrate of your video recording, as higher bitrates translate to larger file sizes. A high bitrate 1080p video captured at 60fps might require a more substantial capacity SD card compared to a lower bitrate 1080p video recorded at 30fps. As a general rule, it’s recommended to choose an SD card with a larger capacity than required to ensure sufficient storage space for your videos.



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