What is an SD Card?
SD cards, or Secure Digital cards, are a type of removable flash memory card commonly used for storage in digital cameras, smartphones, tablets, media players, gaming systems, and more. The SD standard was first introduced in 1999 by Panasonic, SanDisk, and Toshiba, with the goal of creating an interoperable, secure, removable memory card format (Digital SD Card Breakdown).
SD cards store data in flash memory chips encased in a small plastic shell. The cards are re-recordable, allowing you to reuse them multiple times. Over the years, SD card capacities have grown enormously – from just a few megabytes initially to multiple terabytes today (From Megabytes to Terabytes). Improvements in speeds have also enabled SD cards to support high bitrate 4K/8K video recording and other data-intensive uses.
While physically resembling a postage stamp in size, SD cards pack tremendous storage capacity into a highly portable form factor. Their reliability, ubiquitous compatibility, and ever-increasing capacities have made them a vital storage medium for consumer electronics over the past two decades.
SD Card Formats
There are three main types of SD card formats: SD, SDHC, and SDXC. Each format has differences in capacity and speed.
SD cards have a maximum capacity of up to 2GB. The SD format was the original version of SD cards introduced in 1999. SD cards use the FAT16 or FAT32 file system.
SDHC (Secure Digital High Capacity) cards have a capacity between 2GB and 32GB. The SDHC format was introduced in 2006 to support cards with more storage. SDHC uses the FAT32 file system.
SDXC (Secure Digital Extended Capacity) cards range from 32GB to 2TB. The SDXC format debuted in 2009 for cards with even greater storage needs. SDXC uses the exFAT file system.
While the formats vary in how much data they can hold, their physical size is identical. SD, SDHC and SDXC cards will all work in SD card readers and devices. The difference is their maximum capacity limit and file system.
SD Card Speed Classes
SD cards have speed classes that indicate the minimum guaranteed speeds they support. Higher speed classes allow for faster read and write speeds, which improves performance for recording high-resolution video, transferring large files, or running applications off the SD card.
The main SD card speed classes as defined by the SD Association are:
- Class 2 – Minimum write speed of 2 MB/s
- Class 4 – Minimum write speed of 4 MB/s
- Class 6 – Minimum write speed of 6 MB/s
- Class 10 – Minimum write speed of 10 MB/s
There are also UHS Speed Classes that support faster speeds:
- UHS Speed Class 1 (U1) – Minimum write speed of 10 MB/s
- UHS Speed Class 3 (U3) – Minimum write speed of 30 MB/s
Cards with UHS ratings are optimized for high resolution video recording and burst mode photography. The higher U3 class supports 4K video recording. Always check your device specifications to ensure compatibility with UHS cards.1
Do Desktops Have SD Card Readers?
Most desktop computers do not come with built-in SD card readers. The SD card slot is more commonly found on laptops and mobile devices that need to transfer photos and videos from cameras. Desktop PCs are less likely to require mobile data transfer, so an SD card reader is not usually integrated on the motherboard or case.
According to Reddit users, SD card readers are not standard on desktop PC motherboards because the additional hardware cost does not justify the limited usage by desktop owners. The small fraction of desktop users that need to access SD card data can simply use inexpensive adapters or external USB card readers.
Some pre-built desktop PCs from brands like HP and Dell may include integrated SD card readers, but this is less common on custom built desktops or motherboards targeted at PC enthusiasts and gamers. If access to an SD card is required, most desktop PC users can simply install an internal card reader or attach an external USB card reader peripheral.
Overall the limited demand means most desktop PCs rely on external USB card readers to transfer files from SD cards rather than including the card reader hardware directly on the motherboard or case front panel. Easy workarounds exist for the few desktop users that require frequent SD card access.
Types of SD Card Readers
There are two main types of SD card readers for desktop computers – internal and external. Internal card readers are installed directly into a desktop computer’s motherboard or an available expansion slot. External card readers connect to the computer externally via a USB port.
Internal card readers have the advantage of faster read and write speeds since they interface directly with the computer’s motherboard. However, they require opening up the computer to install and take up an internal expansion slot. External USB card readers are much easier to set up – you simply plug them into an available USB port. The downside is that USB 2.0 readers have slower transfer speeds. USB 3.0 external readers can reach speeds comparable to internal readers.
For most home desktop users, an external USB SD card reader is the simplest option. But pros working with large media files may want the performance edge of an internal reader. There are tradeoffs either way.
Installing an Internal SD Card Reader
Installing an internal SD card reader allows your desktop computer to read SD cards like a built-in feature. Here is a step-by-step guide to installing an internal SD card reader:
- Purchase an internal SD card reader that is compatible with your desktop’s motherboard and available drive bays. Make sure the connector type matches your motherboard (e.g. SATA, IDE).
- Open up your desktop computer case and locate an available 3.5″ or 5.25″ drive bay to mount the SD card reader.
- Insert the SD card reader into the drive bay and secure it with screws. Make sure it is mounted properly and connections are secure.
- Connect the power and data cable from the SD card reader to the appropriate connections on the motherboard.
- Replace the computer case side panel and power up the desktop to allow it to detect the new hardware.
- Install any required drivers for the SD card reader if prompted.
- Once installed, the operating system will automatically detect and mount SD cards inserted into the reader.
With an internal reader installed, SD cards can be accessed like any other drive without needing an external adapter. Just insert the card and it will show up as a removable volume. Make sure to unmount the card before removing it to prevent data loss.
Using an External USB Card Reader
Using an external USB card reader is a simple plug-and-play solution for accessing files on an SD card from your desktop computer.
Here are the steps for using an external USB card reader:
- Insert the SD card into the card reader slot. Make sure the card is oriented correctly with the gold contacts facing down into the reader.
- Plug the USB cable from the card reader into an open USB port on your desktop computer. Many external card readers use a standard USB-A connector that will plug into a rectangular USB port.
- The computer should automatically detect the card reader and SD card. You may get a popup notification that new hardware has been detected and is installing.
- Open File Explorer on Windows or Finder on Mac. The SD card should show up as a removable drive.
- You can now access, copy, move or delete files and folders on the SD card through the file explorer just like any other drive.
- When you are finished, right click on the SD card drive and select “Eject” before physically removing the card from the reader.
Most USB card readers are plug-and-play and do not require any driver or software installation. However, you may need to install software included with the card reader for added functionality. Always safely eject the SD card before removing it from the reader.
For more tips, see https://www.howcast.com/videos/383523-how-to-use-an-sd-card-reader
Max SD Card Size for Desktops
Most desktop computers can support SD cards up to 2TB in size. This is the maximum capacity currently available for SDXC cards, which were introduced in 2009 to support capacities higher than 32GB.
The SDXC specification allows for cards up to 2TB, with plans to eventually support up to 128TB as storage technology advances. To use cards larger than 32GB, your computer’s SD card reader and operating system need to support the SDXC standard.
Windows 7 and newer versions support SDXC. For Windows XP, you may need to install an update or driver to enable SDXC compatibility. The SD card reader built into your desktop also must be SDXC-compliant.
Most name brand desktops from the past 5-10 years should have no problem reading a 2TB SDXC card. However, if your desktop is older, you may want to verify SDXC support before purchasing a high capacity SD card.
Overall, 2TB is considered the current maximum SD card size that is widely compatible with desktop computers. Higher capacity SD cards are available but may not work unless you have a newer system and reader that specifically supports capacities over 2TB.
Sources:
https://answers.microsoft.com/en-us/windows/forum/all/maximum-capacity-sd-card/06668045-7313-4e0e-8839-a7ca611d143c
https://www.kingston.com/en/blog/personal-storage/microsd-sd-memory-card-guide
Software to Access SD Cards
There are several software options for reading SD cards on Windows desktops:
- Windows File Explorer – Windows comes with built-in capability to read SD cards through File Explorer. Just insert the SD card and open File Explorer to access the contents.
- Disk Management – This built-in Windows tool can also be used to view info about inserted SD cards and format them if needed.
- SD Card Reader Utilities – Many SD card reader manufacturers provide their own utility software for accessing SD cards, like Lexar Image Rescue and SanDisk SecureAccess.
- File Management Software – Third party programs like IObit Unlocker and Paragon ExtFS can provide added functionality for accessing SD card contents.
Many of these SD card software utilities offer features like recovering deleted files, monitoring disk health, optimizing performance, and securing sensitive data.
SD Cards on Desktops – Final Tips
When using SD cards on your desktop PC, here are some final tips to optimize performance, security, and longevity:
For security, encrypt your SD card to prevent unauthorized access if it gets lost or stolen. Windows includes BitLocker encryption, while third party options like Veracrypt are also available. Also be sure to eject the SD card properly before removing it to prevent corruption.
To maximize performance, choose SD cards with faster speed classes and capacities up to 2TB for desktops. Class 10 and UHS-I or UHS-II cards offer faster read/write speeds. Regularly formatting the SD card can also help maintain speed over time.
For maintenance, format your SD card on a regular basis, clean the contacts gently with rubbing alcohol, and keep cards away from moisture, dust, and extreme temperatures. Avoid using the same card across multiple devices to prevent corruption. Following these tips will optimize longevity of your SD cards.
With the right SD card reader hardware and some care in handling, SD cards can be an easy way to add removable storage and data transfer capabilities to any desktop PC.