Why Proper Data Transfer is Important for the Security of Your Files

Transfer data from laptop to external hard drive (HDD or SSD) seems like a simple task—until you encounter lost files, slow copy speeds, or format incompatibility. Transfer errors can be costly, from lost family photos to corporate documents that cost thousands to recover.

Modern laptops are often equipped with fast NVMe drives, but their volume is limited. External drives (Seagate Backup Plus, WD My Passport, Samsung T7 Shield) solve the problem of lack of space, but require a competent approach to transfer. For example, copying 500 GB of data over USB 2.0 will take 10 times longer than USB 3.2 Gen 2 — and many users don’t even check the port version.

This article will help you avoid common mistakes: from choosing the wrong cable to ignoring file integrity checks after copying. We will analyze 8 current transfer methods (including little-known ones), compare them in terms of speed and reliability, and also provide a checklist for preparing the drive. We will pay special attention transferring system files and programs - here 90% of users make a critical error that makes it impossible to run software from an external drive.

1. Preparing an external hard drive: formatting and checking

Before transferring data, the external drive must be prepared. If the drive is new, it may be formatted in NTFS (for Windows) or APFS (for Mac), but may not always be compatible with your system. For example, exFAT Suitable for cross-platform use, but does not support files >4 GB in older versions of Windows.

How to check the current disk format:

  • 🖥️ On Windows: open This computer → RMB on disk → Properties → section File system.
  • 🍎 On Mac: launch Disk Utility → select the drive → look at the line Format.
  • 📊 On Linux: enter in terminal 
    lsblk -f
    and find the column FSTYPE.

If the format is not suitable, the disk must be reformatted. Important: this will delete all data on it! Optimal for Windows NTFS (maximum compatibility), for Mac - APFS or Mac OS Extended. To exchange between systems, select exFAT.

⚠️ Attention: Formatting in FAT32 limits file size to 4 GB. If you are transferring 4K video or disc images, this format will not work.
📊 How much data do you usually transfer?
  • Up to 100 GB
  • 100–500 GB
  • 500 GB–1 TB
  • More than 1 TB

2. Method 1: Transfer via USB cable (easiest method)

The most common way is to connect an external drive to a laptop via USB. Speed depends on port and cable version:

USB versionMax. speedConnector colorSuitable for
USB 2.0480 Mbit/s (~60 MB/s)BlackDocuments, photos
USB 3.0/3.1 Gen 15 Gbit/s (~600 MB/s)BlueFull HD video, games
USB 3.2 Gen 210 Gbit/s (~1.2 GB/s)Red/orange4K video, large databases
Thunderbolt 3/440 Gbit/s (~5 GB/s)USB-C with lightningProfessional tasks

How to transfer data:

  1. Connect the drive to the laptop (use the original cable or a certified USB-C/Type-A).
  2. Open Explorer (Win) or Finder (Mac).
  3. Drag and drop files with your mouse or use keyboard shortcuts:
    • 🖱️ Ctrl + C → Ctrl + V (Windows)
    • ⌘ Command + C → Command + V (Mac)
  • Wait until the copying is complete (do not remove the disc until the notification appears!).
    • ⚠️ Attention: If the copy speed drops below 10 MB/s, check:
    • 🔌 Cable - try replacing it with a shorter one (length >1 m reduces speed).
    • 💽 Disk status - run chkdsk /f on the command line (Windows) or First Aid in Disk Utility (Mac).

    The original cable is connected|The disk is formatted in the required file system|There is enough free space on the disk (minimum +10% of the data volume)|Programs that use portable files are disabled (for example, Photoshop with an open project)-->

    3. Method 2: Using a SATA/USB adapter for internal drives

    If you have an internal HDD or SSD from an old laptop (for example, Toshiba MQ01ABD or Samsung 860 EVO), it can be connected as external using an adapter SATA-to-USB. It's cheaper than buying a new external drive and allows you to use up to 8TB of storage.

    Step by step instructions:

    1. Buy an adapter with a chip ASMedia or JMicron (they support UASP to speed up the transfer).
    2. Remove the disk from the laptop (unscrew the back cover, disconnect the cable).
    3. Connect the drive to the adapter, then the adapter to the laptop via USB 3.0+.
    4. If the disk is not detected:
      • 🔧 Check if it is included in Disk Management (Windows).
      • 🔄 Try a different USB port.
      • 🛠️ Update the adapter driver via Device Manager.

    The speed of such a connection will be lower than that of native SATA III (maximum ~400 MB/s vs. 550 MB/s), but higher than most external HDDs. For example, WD Blue SA510 in the adapter it will show ~380 MB/s when reading, and the same disk in the box WD Elements - only ~120 MB/s.

    1. Open Device Manager.
    2. Find your adapter in the section USB controllers.
    3. In the properties tab Politics select Better performance.

    This will speed up copying by 20–30%.-->

    4. Method 3: Transfer over local network (for large volumes)

    If you have a second computer or NAS (For example, Synology DS220+), you can transfer data over a local network. This is convenient for volumes >1 TB, since it does not require a physical disk connection. Speed depends on Wi-Fi or Ethernet standard:

    • 📶 Wi-Fi 5 (802.11ac): up to 866 Mbps (~100 MB/s actual speed).
    • 📶 Wi-Fi 6 (802.11ax): up to 2.4 Gbit/s (~200 MB/s).
    • 🔌 Gigabit Ethernet: up to 1 Gbps (~110 MB/s).
    • 🔌 2.5G/5G/10G Ethernet: up to 10 Gbps (~1 GB/s).

    How to set up sharing (using Windows as an example):

    1. Connect the external drive to the second PC.
    2. Open Properties disk → tab Access → Share.
    3. B Security add user Everyone with rights Read/Write.
    4. On your main laptop, open Network in Explorer and find the shared drive named PC.

    For Mac use Sharing in System settings → File sharing. To speed things up, connect your computers directly via Ethernet-cable (required crossover cable for older models or any LAN cable for modern network cards with Auto MDI-X).

    How to check the real network speed?

    Use the utility iPerf3:

    1. Install iPerf3 on both computers (download here).
    2. On the second PC, start the server: 
      iperf3 -s
    3. On your main laptop, run the client: 
      iperf3 -c [IP_адрес_второго_ПК]
    4. Compare the result with the theoretical maximum of your equipment.

    If the speed is below 50% of the maximum, check the cables, network card drivers or router settings.

    5. Method 4: Cloud services for temporary storage

    If physical transfer is not possible (for example, you are on a business trip), you can use cloud services. They are suitable for volumes up to 50–100 GB, since free plans are limited:

    ServiceFree volumeMax. file sizeDownload speed*
    Google Drive15 GB5 TB~10 MB/s
    Yandex Disk10 GB50 GB~5 MB/s
    Mega20 GB—~15 MB/s (with encryption)
    Dropbox2 GB50 GB (via desktop software)~8 MB/s
    Mail.ru Cloud8 GB2 GB~3 MB/s

    *Speed depends on your internet provider and tariff.

    How to transfer data via the cloud:

    1. Upload files to the service from your laptop (via a browser or desktop application).
    2. Connect the external drive to another device (for example, a smartphone or a second PC).
    3. Download files from the cloud to disk.

    Advantages of the method: access from anywhere in the world, backup. Disadvantages: volume limitation, dependence on Internet speed, risk of data leakage (use services with end-to-end encryption, like Mega or pCloud).

    💡

    To transfer >100 GB, the cloud will cost more than a physical disk. For example, 1 TB in Google Drive costs 500–600 rubles/month, and an external HDD Seagate Expansion 1TB — about 4,000 rubles (one-time).

    6. Method 5: Disk cloning (for system transfer or full copy)

    If you need to transfer not only files, but also the operating system with programs (for example, when replacing HDD on SSD), disk cloning will be required. To do this, use specialized software:

    • 🛠️ Macrium Reflect (free version for home use).
    • 🖥️ Clonezilla (free, but difficult for beginners).
    • 💻 Acronis True Image (paid, but with support for cloud backup).
    • 🍎 Carbon Copy Cloner (for Mac, $40).

    Instructions for Macrium Reflect:

    1. Connect the external drive to your laptop.
    2. Run Macrium Reflect and select the source drive.
    3. Click Clone this disk → specify the target drive.
    4. Select Sector by sector copy for an exact copy (important for system drives).
    5. Start cloning (process will take 1-3 hours for 500 GB).

    After cloning, you can boot from your external drive (if it supports booting) or extract the files individually. Please note: cloned Windows may not run on other hardware due to differences in drivers.

    ⚠️ Attention: When cloning to a smaller disk (for example, from 1 TB to 500 GB), use the option Intelligent Sector Copy in Macrium Reflect — it skips empty sectors and compresses data.

    7. Common mistakes and how to avoid them

    Even experienced users make mistakes when transferring data. Here are the most common:

    1. Ignoring file verification after copying. Always compare folder sizes and checksums (MD5 or SHA-1). To do this, use the utilities:
      • 🖥️ WinMD5Free (Windows).
      • 🍎 md5 in the terminal (Mac).
      • 🐧 
        md5sum имя_файла
        (Linux).
  • Using incompatible file systems. For example, NTFS does not support Mac permissions (chmod), and APFS Windows cannot read it without additional software.
  • Transferring open files. If the file is used by a program (for example, Outlook with the email database), it may not be copied completely. Close all applications before transferring.
  • No backup. Before mass copying, create a backup of important data on another medium.

    • Another common problem is file fragmentation on an external HDD. If you transfer a lot of small files (like photos), the drive will slow down over time. Solution: after copying, defragment the disk using the utility Defraggler (Windows) or diskutil secureErase (Mac).

    💡

    To speed up copying a large number of small files (for example, a folder with 10,000 photos), archive them in ZIP or RAR before transfer. This will reduce time by 30–50%.

    8. How to choose an external hard drive for data transfer

    The choice of external drive depends on the tasks:

    • 💼 For work: SSD (For example, Samsung T7 Shield 1TB) - speed up to 1000 MB/s, shockproof housing.
    • 🎮 For games: HDD 7200 rpm (for example, WD Black P10 2TB) - cheaper than SSD, but slower.
    • 📸 For photo/video: HDD with hardware encryption (for example, Seagate IronWolf 4TB) - reliability and large volume.
    • 🔒 For confidential data: SSD with hardware encryption (for example, SanDisk Extreme Pro with AES-256).

    Key parameters when choosing:

    ParameterRecommendationWhy is it important
    InterfaceUSB 3.2 Gen 2 or Thunderbolt4K video copy speed
    Form factor2.5" (for SSD) or 3.5" (for HDD >4TB)Affects portability and capacity
    Impact resistanceMinimum 1000G (for SSD)Fall protection
    Warranty3–5 yearsManufacturer reliability
    SoftwareIncluded (for example, WD Discovery)Automatic backup

    Avoid unbranded drives (such as "no-name" on AliExpress) - they often use low-quality controllers, which leads to data loss after 1-2 years. Optimal price/quality ratio Western Digital, Seagate And Samsung.

    FAQ: Answers to frequently asked questions

    Is it possible to transfer installed programs to an external drive and run them from there?

    Most programs (eg. Adobe Photoshop, Microsoft Office) are tied to the Windows registry and will not work from an external drive. Exceptions:

    • 🎮 Portable versions (For example, PortableApps).
    • 💻 Programs without installation (For example, GIMP, Blender).
    • 🖥️ Games via Steam (you can move the folder steamapps and connect it in Steam settings).

    To migrate system programs, use virtualization (for example, VMware with an external drive as a virtual drive).

    Why does copying speed drop over time?

    Causes and solutions:

    • 🔋 Disk overheating: External HDDs get hot during prolonged use. Solution: Use active cooling (e.g. stand with fan).
    • 🗃️ Fragmentation: When copying small files, the speed decreases. Solution: Defragment the disk before use.
    • 🔌 Lack of nutrition: The laptop's USB ports may not supply enough current. Solution: use Y cable or connect the drive to charging.
    • 💽 Interface Limits: USB 3.0 actually gives ~300–400 MB/s, not 5 Gbit/s. Solution: For speeds >500 MB/s use Thunderbolt.
    How to transfer data from a laptop that won't turn on?

    If the laptop does not start, but the disk is working:

    1. Remove the internal drive and connect it to another PC via SATA-USB adapter.
    2. If the disk is not detected, use recovery utilities:
      • 🖥️ R-Studio (paid, but effective).
      • 💻 TestDisk (free, for advanced users).
      • 🍎 Disk Drill (for Mac).
  • If the disk is physically damaged (knocks, does not rotate), contact a laboratory (for example, ACELab or HDD Recovery). Do-it-yourself repairs may make the problem worse.

    • The cost of data recovery in the laboratory: from 5,000 rubles for logical errors to 50,000 rubles for repairs in a clean room (if the plates are damaged).

    Is it possible to use an external SSD as an internal one for a laptop?

    Yes, if:

    • 🔧 The laptop supports disk replacement (check the model on the manufacturer's website, for example, Lenovo or HP).
    • 💽 SSD has a form factor M.2 2280 (for slot NVMe) or 2.5" (to replace HDD).
    • 🖥️ Do you have an adapter (for example, M.2 to USB to clone data before installation).

    Examples of compatible SSDs:

    • 💻 Samsung 980 Pro (PCIe 4.0, up to 7000 MB/s) - for gaming laptops.
    • 💼 Crucial MX500 (SATA, up to 560 MB/s) - for office PCs.
    • 🍎 WD Black SN850X (PCIe 4.0) - for MacBook Pro (adapter required).

    After replacing the disk, you may need to reinstall Windows/macOS or transfer your license (for example, via Microsoft Account).

    How to protect data on an external drive from viruses?

    Security measures:

    • 🛡️ Encryption: use BitLocker (Windows Pro) or FileVault (Mac). For cross-platform encryption − VeraCrypt.
    • 🦠 Antivirus: Scan the disk after connecting to other people's PCs (for example, Kaspersky Rescue Disk).
    • 🔒 Disabling autorun:
      • On Windows: gpedit.msc → Computer Configuration → Administrative Templates → Windows Components → Autorun Policies → Disable autorun.
      • On Mac: System Preferences → Security and Safety → General → Disable "Open 'safe' files after download".
    • 📂 Backup: Store critical data in duplicate (for example, on disk and in the cloud).

    If the disk is already infected, do not open files from it! Connect the drive to a clean PC with antivirus installed and scan it with Safe Mode.