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11 February 2024  Jennifer Thatcher  Technology Manager of Test Dept.
 

Summary
Boost your Mac's reading speed when working with an external hard drive by exploring the causes and solutions in our comprehensive guide. Uncover expert tips to enhance performance and enjoy a seamless experience.



Table of contents

table iconI. Reasons for slow reading of Mac mobile hard disk and corresponding solutions
table iconII. Use Renee Undeleter to recover lost data from mobile hard disk
external hard drive slow mac

I. Reasons for slow reading of Mac mobile hard disk and corresponding solutions

1. The file system of the mobile hard disk is wrong or malfunctioning

As the usage time of the mobile hard disk increases, issues such as bad sectors, file system errors, and other failures may arise, impacting the read/write and transmission speed. To address this on a Mac system, follow these steps using Disk Utility:
Step 1: Find and click (Disk Utility) in the launchpad; you can also click (Finder) > (Applications) > (Utilities) to find and open (Disk Utility).
mac applications
find mac disk utility
Step 2: Select your hard disk in the list on the left, and then select the (First Aid) function above.
find first aid in disk utility
Step 3: After clicking First Aid, a confirmation window will appear. The “First Aid” function will check the volume for errors and repair it. Please click (Run) to initiate the hard disk checking and repairing process. After repairing, open the files of the mobile hard disk to verify if the reading speed has returned to normal.
Kind tips

Some users may have read elsewhere that the fsck command can repair disks. fsck is an acronym for File System Consistency Check and is a command-line tool for checking and repairing the structure of a hard drive. Articles also mention using the (fsck -fy) command to repair, but this method requires single-user mode and may not be successful.

Test results show that using only the (fsck -fy) command results in warnings and errors, and smooth repair is not possible. Instead, choose the appropriate fsck command based on the disk format. For example, using (fsck_msdos /dev/disk2) checks and repairs the /dev/disk2 disk with the FAT file system. If the target disk has a different file system, replace it with the corresponding command (e.g., fsck_hfs for HFS, fsck_exfat for exFAT, fsck_apfs for APFS).

Using the fsck command to repair disks requires knowledge and it is recommended to seek help from official after-sales service or technical departments instead of attempting it yourself.

Test the fsck -fy command

2. There are many duplicate files in the mobile hard disk or multiple applications running on the hard disk at the same time

If there are numerous photo, video, and audio files saved on the mobile hard disk, with many duplicates taking up significant storage space, or if multiple applications are running concurrently while transferring files or performing other operations, it can lead to slow reading speed on the mobile hard disk. Use the Finder to organize and remove duplicate files from the mobile hard disk. Additionally, close unnecessary applications and perform one operation at a time to address the issue of slow reading on the mobile hard disk.

3. The power of the USB port is insufficient

If your mobile hard disk is connected to a Mac computer and you can view files, but the operation is slow, it may be due to insufficient power. Certain mobile hard drives require more power than the USB interface can provide for normal operation, as different drives have varying startup and operating currents.
If you want to solve the power shortage problem, you can take the following two methods:
1. The first method is to purchase a mobile hard disk dual USB power supply data cable. It has a dual USB interface that can be connected to your computer for enhanced power supply. The other end is used to connect to the mobile hard disk.
Mobile hard disk dual USB interface power supply
2. The second method is to purchase a USB hub with supplemental power. It is superior to the first method in that it allows you to connect multiple mobile hard drives simultaneously without concern for power shortage or excessive use of computer USB ports.
usb hub

4. The mobile hard disk is infected with virus

Connect the infected mobile hard drive to a computer and use anti-virus software to scan and remove virus files.

5. Format the mobile hard drive for defragmentation

When the mobile hard disk stores a large number of files and undergoes frequent data deletion and saving over a long period of time, disk fragmentation may occur. This can result in slower computer performance when accessing data on the mobile hard disk. To address this issue, you can transfer the files from the mobile hard disk to other disks, format the hard disk to clear all data, and then store the original files back onto it to achieve defragmentation.
The (Erase) function in Disk Utility is equivalent to the format function in Windows system. It can change the file system of the hard disk, and can also clear all the data on the hard disk, so as to solve some hard disk failure problems. Note: Please make a data backup before operation .
Step 1: Find and click (Disk Utility) in the launchpad; you can also click (Finder) > (Applications) > (Utilities) to find and open (Disk Utility).
Step 2: Select the target mobile hard disk on the left, then click (Erase) on the top, select the file system format of the hard disk in the pop-up window, and then click (Erase).
erase hard disk drive when it is not showing up in mac
Kind tips● If the mobile hard disk is used to store Time Machine backups or is only used for Mac systems, you can choose (Mac OS Extended (Journaled));
● If the mobile hard disk needs to be used to store data in both Mac and Windows systems, then you can choose (ExFAT).
● If you want to use the hard disk in some older models that do not support exFAT, you need to select (MS-DOS (FAT)), which is equivalent to (Fat32), but the FAT file system cannot be used on hard disks larger than 32GB.
● In High Sierra, Apple introduced a new file system called Apple File System (APFS), which aims to solve the core problems of the HFS+ (ie Mac OS extension) file system. APFS is optimized for flash memory and solid-state storage devices, has design features such as copy-on-write, and uses I/O coalescing to improve performance, so (APFS) options can also be considered.
Step 3: After erasing the disk, save back the original files in the mobile hard disk, and then try to open the file to test the reading speed.
If you have not backed up the data before formatting (erasing) the hard disk, please try the following methods to recover lost data from the mobile hard disk.

II. Use Renee Undeleter to recover lost data from mobile hard disk

1. What is Renee Undeleter?

Renee Undeleter is a software for restoring data files. It can recover lost data from accidental deletion, emptying the recycle bin, or disk/storage formatting. The software includes file recovery, format recovery, partition recovery, and image creation modules to solve all data loss issues.
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Multiple scan modes Fast partition scan, whole partition scan and whole disk scan;

Supported file types Image, video, audio, text, email and so on;

Image creation Create a partition image to read and back up data;

Supported devices SD card, SDHC, SDXC, USB flash drive, hard disk and computer.

Easy to use Recover data by 3 steps;

Multiple scan modes Fast partition/whole partition/whole disk scan;

Supported devices SD card/USB/hard disk.

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2. How to use Renee Undeleter to recover lost mobile hard disk data?

As a professional data recovery software, Renee Undeleter not only has comprehensive functions, but also has a very simple operation process. The specific operation steps are as follows:
Step 1: Download, install and run Renee Undeleter on a Mac computer, and select the (Whole Partition Scan) option on the main interface.
Note : In order to avoid data overwriting, it is not recommended to install Renee Undeleter on an external disk that loses data.
select whole partition scan in renee undeleter on mac
Data recovery function introduction:
File recovery: Quickly retrieve files lost due to accidental deletion or emptying the recycle bin.
Format recovery: Quickly recover files lost due to inaccessible or formatted partitions.
Partition recovery: Partition information can be analyzed and obtained, and the entire partition can be fully scanned.
Create a mirror: A mirror can be created for a partition to back up the current partition state.

Step 2: Next select the hard drive partition where you want to recover data. After the selection is complete, click (Next).
Select the partition to scan for the Mac version
Step 3: Wait for the scan to complete. The scan time will vary based on the hard disk partition size. During the scan, you can preview files by double-clicking on them. If you find the file you want to recover, check it and click the “Recover” button. The scan will then stop and the file recovery process will begin. Alternatively, you can wait for the scan to finish, select the files you want to recover from the scan results, and click the “Recover” button to save them in other hard disk partitions.
preview before recovery
Kind tipsIf the mobile hard disk cannot be displayed or used normally on the Mac computer, please check the reasons and solutions for the Mac computer not recognizing the mobile hard disk.