Why is exFAT slow on Windows 11? How to make exFAT partition run faster? In this post, you will get both common reasons and useful solutions to fix exFATslow Windows 11.
exFAT can sometimes feel slow on Windows 11 due to several reasons related to how the file system works and how Windows handles it. Here are the main factors that might cause exFAT performance issues:
1. Lack of journaling and file system overhead
ExFAT is designed as a lightweight file system without journaling (unlike NTFS). While this reduces overhead for simple storage, it also means less protection and optimization for frequent small file operations. As a result, when dealing with many small files or complex file operations, exFAT can appear slower than NTFS.
2. Driver and kernel-level support
Windows 11 supports exFAT natively, but exFAT drivers are generally less optimized compared to NTFS drivers because NTFS is the primary Windows file system. Some system-level caching and optimization features available for NTFS don’t fully apply to exFAT, which can reduce speed.
3. Fragmentation
exFAT does not handle fragmentation as well as NTFS. Over time, the file system may become fragmented, causing slower read/write speeds. Fragmented exFAT volumes can especially slow down performance with large files or high I/O workloads.
4. Hardware and device compatibility
The speed of exFAT drives also depends heavily on the hardware (USB drives, SD cards, external HDDs/SSDs). Some external drives or USB sticks formatted as exFAT may have slower flash memory or controllers that don’t handle exFAT efficiently, causing bottlenecks.
5. Transfer type and block size settings
ExFAT performance can be affected by the allocation unit size (cluster size) chosen at formatting. A mismatched cluster size for your workload (e.g., very small clusters for large files) can slow down file transfers.
If you’ve noticed slow performance with your exFAT-formatted drive on Windows 11, you’re not alone. Fortunately, there are several practical solutions you can try to enhance its speed. Let’s walk through the key fixes step by step.
Before diving into complex tweaks, start with the basics. Sometimes, slow speed issues stem from faulty or loose cables, outdated USB ports, or even malfunctioning external enclosures.
Carefully unplug and reconnect the drive using a different USB port—preferably a USB 3.0 or 3.1 port for faster performance. Also, test with a different cable or PC to rule out hardware issues.
Reformatting can help optimize your exFAT drive for better compatibility and efficiency. But be sure to back up your data first, as formatting will erase everything.
Step 1. Double click “My Computer/This PC” to open File Explorer. Right-click the USB flash drive you need to format and select “Format…”.
Step 2. In the pop-out mini window, choose “exFAT” under File System volume, but this time manually set the Allocation Unit Size to 128KB or 256KB—ideal for large files.
Step 3. Tick “Quick Format” and click “Start”. A proper format tailored to your use case can make a noticeable difference in read/write speeds.
Although defragmentation mainly benefits HDDs, some exFAT drives—especially mechanical ones—can gain performance boosts when data is better organized.
Step 1. Search for and open Defragment and Optimize Drives from the Start menu.
Step 2. Select your exFAT drive (if supported), and click Optimize.
If the defrag tool doesn’t recognize your drive (common with removable or USB drives), consider third-party optimization tools that support exFAT.
AOMEI Partition Assistant is a powerful and user-friendly disk management tool designed to optimize and maintain your hard drive's performance. Among its wide range of features, one particularly useful function is Disk Defrag, which can scan your drives, identify fragmented files, and rearrange them to be stored in contiguous clusters. This process helps reduce read/write times and enhances system responsiveness.
Step 1. On the main interface of AOMEI Partition Assistant, all your disks are listed. Find the disk you want to defragment (take Disk 0 as an example), right-click and select Disk Defrag.
Step 2. After that, all NTFS partitions on the disk will be listed. Because this function can only run on NTFS partitions currently. You can click Analyze to check partition.
Step 3. Wait a moment, your partition status will be expressed in the form of scores. There are three results:
Step 4. You can click “Details” to view more information about the analysis results, or you can directly click “Defrag” to perform defragment.
Step 5. After the defragmentation is completed, the partition will be scored according to the defragmentation result.
Outdated or corrupt drivers can throttle performance, especially for USB controllers and disk interfaces. Begin by opening Device Manager from the Start menu.
Step 1. Expand Disk Drives and Universal Serial Bus controllers, right-click each item, and choose Update driver > Search automatically.
Step 2. Also, check for Windows updates by going to Settings > Windows Update and clicking Check for updates. Install everything available and restart your PC.
In summary, exFAT may perform slowly on Windows 11 due to many factors. Fortunately, you can boost performance by checking hardware connections, properly formatting with ideal allocation size, defragmenting the drive using tools like AOMEI Partition Assistant, and keeping drivers and Windows updated. With the right adjustments, exFAT drives can run more efficiently and deliver noticeably improved speed on Windows 11 systems.