[Answered] Why Is My SD Card Slow and How to Make It Faster

Why is SD card slow? How to increase SD card transfer speed? If you find that your SD card is slow to read and write files, read this article to understand the reasons behind it. 6 solutions are explored here.


By Phoebe / Updated on March 6, 2024

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Why does my SD card take so long to transfer files?


Why is my Micro SD card slow when I copy video from my smartphone camera to an SD card? It copies at 10mb/s which seems to take a long time. It bothers me that the transfer speed is so slow when I want to copy anything from my phone to my computer. Does anyone know what could go wrong here?"

- Question from Quora

The problem of why is SD card slow can be caused by several factors. Over time, residual data accumulates as files are repeatedly written and erased, internally affecting the card's speed during the writing of new data. In addition, the reasons for slow writing speed of SD card are:

Low Grade: SD cards come in different speed grades such as Level 2, Level 4, Level 6, Level 10, etc. The higher the level, the faster the card speed.

Old or low-quality cards: Old or low-quality SD cards may not have the same read/write speeds as new, high-quality cards.

File system: The file system used on the SD card affects its speed. For example, FAT32 may not be as efficient as exFAT or NTFS, especially for larger files.

Fragmentation: If the files on the SD card are heavily fragmented, it will slow down the read and write speeds.

Storage Capacity: SD cards with larger storage capacities tend to be slower than SD cards with smaller capacities.

Device Compatibility: If your device is older or doesn't support high-speed SD cards, you may experience reduced performance.

Physical damage or wear: If the contacts are dirty or damaged, or the card itself is physically damaged, the card may not function optimally.


How to fix slow SD card

To solve the problem of why is SD card slow, here are 6 suggested tips that can potentially improve file transfer speeds on all types of SD cards:

Way 1. Connect to a new USB port or another PC

Consider using a USB hub, a practical device that expands one Universal Serial Bus (USB) port into multiple ports, allowing simultaneous use. However, if the USB hub/port is outdated, it may negatively impact SD card transfer speeds. If you connect your SD card to your computer via a USB hub, switching to a newer hub like HUB 3.0 or 3.1 can alleviate the SD cards why is write speed slower problem.

Way 2. Change the card reader

Memory card readers help access data on various memory card types such as CompactFlash (CF), Secure Digital (SD), or MultiMedia Card (MMC). Most card readers also offer writing capabilities, effectively acting as pen drives. With the right SD card reader, you can benefit from:

▪ Read/write at full speed for high-performance

▪ High-speed backup of high-resolution images and 4K videos

▪ Built-in USB-A port for wireless PC connection

Way 3. Convert SD card to NTFS (no data loss)

As mentioned before, the SD card's file system can significantly affect SD card transfer speed, especially when dealing with large files. FAT32 microSD cards are limited in transferring individual files larger than 4GB, while NTFS exceeds this limit. To speed up SD card transfers, consider converting the file system to NTFS.

How to convert an SD card to NTFS format? You can format using Windows built-in tools such as Disk Management, Diskpart, and File Explorer. However, this formatting process may come with certain disadvantages such as data loss and the volume is too big for FAT32 error.

To overcome these challenges, we recommend using AOMEI Partition Assistant Professional. This comprehensive partition manager allows you to convert FAT to NTFS and vice versa without formatting. Additionally, it breaks the file system size limit and can format drives larger than 32GB as FAT32. Additionally, it helps in formatting corrupted SD cards, easily cloning SD cards in Windows, and more.

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Here's how to use AOMEI Partition Assistant Pro to convert SD card to NTFS without losing data:

Step 1. Install and launch AOMEI Partition Assistant Professional Edition.

Step 2. Right-click the drive you want to convert and select Advanced > Convert to NTFS.


Step 3. In the pop-up window, select NTFS by default. Click OK.


Step 4. Now, the SD drive already has an NTFS file system. Click Apply to perform this action.


Way 4. Format SD card to NTFS (data loss)

If your SD card is smaller than 32GB and you have backed up the SD card already, you can format the SD card to NTFS using built-in Windows tools such as Disk Management (DM) to increase the SD card write speed.

Step 1. Open This PC, right-click on the SD card, and select Format.

Step 2. Set the file system to NTFS, click Next, check the Quick Format box, and click OK to format the USB flash drive.


Note: Windows only supports FAT32 and NTFS file systems. If your drive requires other file systems, such as exFAT and Ext 2/3/4, please consider using AOMEI Partition Assistant Pro.

Way 5. Update the Device driver

Sometimes, updated device drivers can affect SD card performance. To speed up SD card transfers, make sure all relevant drivers (such as disk drivers, USB controller drivers, and chipset drivers) are up to date.

Step 1. Insert the SD card into your computer's USB port.

Step 2. Right-click on This PC and select Manage.

Step 3. In the new pop-up window, navigate to Device Manager on the left and click on it.

Step 4. Expand the Disk drives category. Right-click on your SD card drive and select Update Driver Software.


Step 5. In the pop-up window, choose Update Driver button.

Follow the on-screen prompts to complete the update. Repeat this process to update drivers for other categories, such as disk drives.

Way 6. Improve the SD card's performance

After updating your SD card or USB driver, follow these steps to optimize SD card performance by adjusting settings to increase data transfer speeds:

Step 1. Connect the SD card to the corresponding USB port. Right-click the Windows icon on the taskbar.

Step 2. Select Disk Management from the list of options.

Step 3. In the Disk Management window, find the inserted SD card.

Step 4. Right-click on your drive and select Properties. Go to the Policies tab and check the Better performance box.


Step 5. Check Enable write caching on the device under Write-caching policy.

Step 6. Click OK to save your settings.

Final words

In summary, you now understand why is SD card slow and how to correct the problem. To convert SD cards to NTFS without formatting, you can consider PA Pro, which can achieve this goal without losing data.

This versatile program also offers advanced features such as cloning an Android SD card to a larger one without data loss, repairing damaged or damaged SD cards, and moving programs or files from a C drive to a D drive. Windows Server users may find the AOMEI Partition Assistant Server useful.

FAQs about slow SD cards

Q1. What is the service life of an SD card?

Usually about ten years. SD cards store information in flash memory that can last up to 10 years or more under normal use and technology standards. No need for frequent upgrades, reducing electronic waste.

Q2. Do SD cards age over time?

It varies based on factors such as card quality, usage, and environmental conditions. While some cards continue to work fine after years of storage, others fail prematurely due to heavy use.

Q3. Are SD cards more durable than USB drives?

Both rely on NAND flash memory and theoretically have similar lifespans. However, USB drives generally have a longer lifespan due to their larger size and better cooling capabilities.

Q4. Will the SD card slow down my phone?

Yes, if the app is running from an SD card instead of internal memory. SD cards are generally slower than internal storage, and operating system performance may be affected when continuously reading/writing to the SD card.

Phoebe · Staff Editor
Phoebe, an editor at AOMEI Technology, is dedicated to offering optimal solutions for Windows-related concerns, specializing in partition management, disk upgrades, data recovery, and more. During her free time, she enjoys indulging in reading, watching movies, and exploring her passion for cooking.