External SSD Writing Speed Slow? Try These 4 Effective Solutions

Updated by

Linda 

Written by

Sherly 

Updated on April 22, 2024

External SSDs are ideal for businesses or individual users seeking convenient and secure data transfer in large quantities. These devices can be powered through a USB connection to a computer and access data more quickly than an HDD. However, some users have reported that their external SSDs have experienced slow write speeds. This issue has been reported across various brands, including Seagate, Western Digital, and Toshiba. Our team has conducted extensive research on this problem and has compiled 4 effective solutions to address it. These methods have proven helpful for numerous users in resolving the "External SSD Slow Write Speed" issue.

How to Test External SSD Speed Accurately

If you suspect that your external SSD is slowing down, you can confirm your assumption using a command in the command prompt. However, this method can be quite cumbersome for inexperienced users, and there's a high risk of data loss. Consequently, based on our research, we've found a speed measurement software suitable for beginners. The tools Partition Master tool can assist you in obtaining accurate read and write speeds of your external SSD, and it's compatible with any Windows laptop or computer. It boasts a very intuitive interface and guidance, so feel free to download and give this tool a try without worry.

Step 1. Launch AOMEI Partition Assistant. Click the download button to activate the "DiskMark" feature under the "Tools" section.

Click the “Download” button of DiskMark.

Step 2. Click the drop-down box to select the target drive, test data, and block size.

Step 3. After configuring everything, click "Start" to begin the disk test. You'll then see the Sequential or Random read/write speed, I/O, and Delay data.

Compare the test results with the normal speed that the external SSD should have. You can draw a conclusion. If you regularly use your computer for tasks that involve reading large amounts of data from an external SSD, such as video editing or gaming, the slow speed can significantly hinder your experience. Attempt the following solutions to address the issue.

You can check out this video for more information about testing the speed of your SSD.

How to Fix Slow Write Speed Issue on External SSD [4 Solutions]

In this section, you'll discover four effective methods to address the issue of a slow writing speed on an external SSD. Drawing upon the reasons outlined in the previous part, the solutions we propose are as follows:

1. Fix 1. Align the External SSD for 4K
2. Fix 2. Clear Cache on External SSD
3. Fix 3. Choose Better Performance Option
4. Fix 4. Check for Bad Sectors and Free Up Space on External SSD

Optimizing defragmentation on an external SSD is an efficient method to enhance the performance and speed of an external solid-state drive. Follow Fix 1 for guidance.

Fix 1: 4K Align the External SSD

4K alignment refers to the process of aligning partitions on an SSD with the physical storage areas on the SSD drive to enhance data processing efficiency. If the partitions are not correctly aligned, the external SSD might need to access twice the physical segments of the SSD to execute any file operations. This can result in increased read and write times, and the SSD won't function at its optimal level. Hence, it's crucial to perform 4K alignment for your external SSDs.

After numerous tests, we discovered a dependable third-party software called Partition Master. This tool can align SSD 4K on Windows 7, 8, 10, and 11, thereby optimizing external SSD performance and boosting its speed. The outcomes were indeed satisfactory. Click the button to download this tool now.

Here are the steps to align an external SSD with Partition Master tool in American English: 1. **Download and Install**: First, download the Partition Master software from a trustworthy source onto your computer. Make sure you get the version compatible with your OS (Windows, macOS, or Linux). 2. **Start the Software**: After installing, launch the Partition Master application. You'll see a screen showing all connected storage devices. 3. **Choose the SSD**: Locate your external SSD in the drive list. It should be listed by its capacity and drive letter (like "Disk 1" or "E:"). 4. **Check Alignment**: Before going further, check if the SSD is 4K-aligned. Right-click on the SSD partition and select "Properties" or "Check Alignment." If it's not aligned, move to the next step. 5. **Resize/Move Partition**: To realign, you might need to resize or shift the partition. Right-click and pick "Resize/Move Partition." Drag the sliders to create free space at the partition's end. 6. **Create New Partition**: With the free space, right-click and select "New Partition." This will create a 4K-aligned new partition. Allocate the full free space. 7. **Format the Partition**: Choose the freshly made partition and hit "Format Partition." In the formatting window, set the file system (like NTFS, exFAT, or FAT32) as needed. Check the "Align partition to 4K sector" or a similar option. 8. **Apply the Changes**: After formatting, click "Apply" or "Execute 1 Task" to start alignment. The app may warn about data loss; back up crucial files beforehand. 9. **Wait for Completion**: Depending on the SSD's size, alignment could take time. Don't interrupt or shut down during the process. 10. **Confirm Alignment**: Post-completion, double-check the partition properties to verify 4K alignment. Keep in mind, these steps are general guidelines, and exact options and wording may differ based on your Partition Master version. Always be cautious with partitions and backups to prevent data loss.

Step 1. Go to "Toolkit" and choose "4K Alignment".

Step 2. Select the disk that you want to align. Click the "Start" button.

Aside from that, Partition Master has many features to help you manage your SSDs and external SSDs:

• Test SSD read and write speed
• Merge/split partitions on SSD
• Locate bad sectors on external SSD
• Check file system error for external SSD
• Check SSD health on Windows 10/8/7/11
• Check SSD temperature on Windows 10/11
Translation:
• Test SSD read and write speed
• Merge or split partitions on SSD
• Detect bad sectors on external SSD
• Check file system errors for external SSD
• Check SSD health on Windows 10/8/7/11
• Check SSD temperature on Windows 10/11

Feel free to download this tool to manage your external SSD and enhance its performance without any hesitation.

Fix 2: Clear Cache on External SSD

If the external SSD delivers high transfer speeds for a brief time and then slows down after moving a large amount of data, the issue is probably due to excessive caching. To clear the write cache and enhance write performance, follow these steps: 1. Leave the external SSD unused for a while. 2. Connect the external SSD to a computer. 3. Ensure both the computer and the external SSD remain active for an hour or more. This process allows the drive to flush its cache and optimize its performance.

Step 1. Connect the external SSD to a Windows PC > Open Settings > System > click Storage > Select the target external SSD.

Step 2. Click "Temporary files" > Check temp files; click the "Remove Files" button.

Fix 3: Enable Write Caching for External SSD

Write caching is used to enhance performance by utilizing volatile memory (RAM) to buffer write commands sent to storage devices. However, it's important to safely eject the external storage device before disconnecting it from the computer.

Step 1. Connect the external SSD to your laptop/computer; right-click on "My Computer" and select "Manage."

Step 2. Select Device Manager, and expand Disk Drives. Next, right-click the external SSD for which you want to enable or disable write caching, and choose Properties.

Step 3. Click the Policies tab; select Better Performance and Enable write caching on the device.

Enable the write cache

Step 4. Click OK.

Solution 4: Check for Bad Sectors and Free Up Space on External SSD

Bad sectors and low disk space issues can both contribute to a slow external SSD. In this section, you'll learn how to check for bad sectors on your external SSD and how to free up space for it.

Guide 1: Locate Bad Sectors on External SSD

The tool Partition Master can help locate bad sectors by running a disk surface test on your external SSD. Download it and follow these steps:

Step 1. Launch AOMEI Partition Assistant. Right-click the disk that you wish to check and choose “Surface Test”.

Step 2. The operation will be performed immediately, and all bad sectors will be marked in red.

Guide 2: Free Up Space on External SSD

When the storage space on your external SSD becomes insufficient, its performance may also be impacted, resulting in slower read and write speeds. You can free up storage space on your external SSD in various ways, such as deleting unnecessary files and programs or removing duplicate files.

The Partition tool comes with a "analyze disk space" feature; it can analyze the storage structure of your external SSD, helping you quickly identify which files consume the most space and enabling you to delete them with a single click.

Get your computer with Windows ready, and then follow the instructions below to get started.

Step 1. Launch tools Partition Master and go to Discovery. Find and download Space Analyzer under Frequently Used Tools.

Step 2. In the Space Analyzer pop-up window, select the target disk to be analyzed and click Analyze in the upper-right corner.

Step 3. Wait a while, and you'll see the detailed data. Click on Folder/File to view different data types, and click the small folder icon to see more details within the file.

Why Does the External SSD Have Slow Write Speed?

External SSDs are favored due to their speed, so when they slow down, it can be highly frustrating. Here, we've compiled a list of common reasons for external SSD performance degradation. These include:

Here are the translations for the languages you provided in bullet points: 1. ? Too much cache; - English: "Excessive cache"; 2. ⚙️ Insufficient storage space; - English: "Insufficient storage space"; 3. ? The insufficient power supply of the interface; - English: "Inadequate power supply to the interface"; 4. ? External SSD has bad sectors or viruses; - English: "External SSD has bad sectors or is infected with viruses";

When copying large datasets all at once, some external SSD drives might experience performance decline when the drive cache becomes full. Furthermore, storing excessive data or encountering malicious viruses can lead to a slowdown in the external SSD's performance.

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But how do you know and test if your external SSD has become slow? Read on to find out.

Conclusion

With frequent usage, an external SSD might become slower due to excessive cache, fragmentation, a high number of bad sectors, and so on. This article offers several solutions to address these issues, such as clearing cache, defragmenting the SSD, and more. The tool Partition Master can help defragment and optimize the performance of an external SSD with 4K alignment; it also conducts surface tests to detect bad sectors on the external SSD. If you find these methods helpful, please share this article to inform more people about these troubleshooting techniques.

"External SSD Slow Write Speed Frequently Asked Questions"

Is your external SSD still slow? Besides, there are other queries related to the external SSD slow write issue. If you need assistance, read on.

There are several reasons why an SSD may consistently report speeds below its maximum capacity. Firstly, macOS is continually reading and writing data to the boot drive, which can result in suboptimal performance. Secondly, the SSD carries out its own maintenance and garbage collection processes, such as TRIMming, which can affect its speed. When you erase the SSD and boot from the external drive, you might observe speeds closer to the advertised rate. However, once the SSD's write cache becomes full, it will naturally slow down.

This might be due to low disk space or high temperatures (beyond the normal range for an SSD). Allow your SSD to cool down and free up some space on it; then, try loading the game again, and this error should be resolved.

3. How to fix the slow write speed issue on my M.2 SSD?

Overheating, outdated firmware, disk fragmentation, low disk space errors, or inadequate power supply can result in slow write speed issues on an SSD. You can rectify this by enabling write caching, freeing up more space, installing a heat sink for the SSD, or ensuring proper 4K alignment of the SSD.