How to speed up and verify large file transfers with TeraCopy

When you start to move very large files or thousands of small filesWindows Explorer and even TeraCopy can feel incredibly sluggish. Speeds start at 100 MB/s and then plummet, progress bars seem frozen, and occasionally, copies stop for no apparent reason.

If you are also one of those who They verify their copies with checksums If you rely on external hard drives, NAS devices, or older USB drives, it's normal to worry about data integrity. There which is lost with each transfer. The good news is that there's plenty of room for improvement: by combining good hardware, a fine-tuned Windows configuration, and tools like TeraCopy, you can gain speed and, above all, peace of mind.

Why are file copies so slow (even when using TeraCopy)?

Often, the blame lies with one Slow copying of large files It's not TeraCopy or Windows that's the problem, but rather the hardware through which the data passes. A very full mechanical hard drive, a low-quality USB drive, or an outdated port can significantly limit the actual speed far more than theoretically predicted.

When you see the transfer start strong and in a matter of seconds It drops from 100 MB/s to 40 MB/s and stabilizes.There's no reason to worry: this is normal behavior for the cache system and the device itself. The problem arises when the speed graph is erratic, with frequent drops to 0 bytes/byte or very long pauses for no apparent reason.

In those cases there is usually a clear bottleneck at some point in the chainAn outdated USB drive, a corrupted source disk, antivirus software blocking everything, background processes overloading the system, or even a NAS limited by the network. Before blaming the backup software, it's important to understand all these factors.

Beyond the hardware, there is another factor that carries significant weight: Windows configuration and its services. Drivers generics, laptop power modes, overly aggressive antivirus software, or automated tasks such as Windows Defender They can steal a good chunk of performance right when you're copying large amounts of data.

Hardware factors that slow down transfers

The basis of a Fast and stable transfer It's always about the hardware. No matter how sophisticated TeraCopy or any other utility is, it will never be able to run faster than the slowest device involved in the process.

One of the critical points is the type of USB flash drive or external hard drive you useMany cheap memory devices still operate with USB 2.0 or very poor quality chips, and there are no miracles there: not even the best software in the world will overcome the physical write limit of the device.

The USB 2.0 standard theoretically promises 480 Mbit/s (about 60 MB/s), but in practice many drives only achieve around that. 30-35 MB/s peak…and that's under the best conditions. Most budget USB 2.0 drives write at much lower speeds, so if your drive is still of this type, that's usually the main bottleneck.

To notice a real leap, it's worth switching to USB 3.0 or higher external memory or hard drivesHere it is important to look not only at the read speed advertised by the manufacturer, but also at the write speed, which is usually much lower and is the one that matters when copying data to the device.

You also have to keep in mind that The final speed is determined by the slowest link.There's no point in having a fast USB 3.0 flash drive if you connect it to a USB 2.0 port on your PC: everything will be limited to the older standard. Furthermore, USB 2.0 provides less power, which in some cases causes power issues with external drives.

If your computer is relatively recent, it will normally have USB 3.0 ports identified in blueIn older systems, one option is to add a PCIe card with USB 3.x ports, always checking beforehand that the motherboard supports those speeds and that it will not create another bottleneck.

The type of storage The computer's internal components also weigh a lot. Fragmented and almost full mechanical HDD will read data much slower than a SSD modern, which can drastically reduce copy speed, especially when the source is that traditional disk and the destination is something fast like an external SSD or a good USB drive.

Furthermore, the external drive file system It affects both speed and size limitations. Systems such as FAT32 exFAT and exFAT are used for their compatibility with other devices, but NTFS It usually offers better performance on Windows and fewer restrictions, especially with very large files.

Configure Windows properly to avoid losing speed

Once you have the hardware under control, it's time to check to what extent Windows is helping or hindering your copiesThe operating system comes with default settings that work "more or less" for everyone, but they don't always get the most out of external storage drives.

The first thing is to make sure you're using a relatively modern and updated version of WindowsWindows 10 (and later versions) handle current protocols and disks much better than older versions like Windows 7 or even XP, which falls short with recent hardware. Windows 11, the new features of copy and search improve the experience.

It is also essential to keep the chipset drivers and USB-related controllersWhen you install Windows, the system usually uses generic drivers, which work, yes, but don't always take full advantage of your hardware's potential. Going to your motherboard manufacturer's website and downloading the latest chipset and USB drivers can significantly improve transfer performance.

If you're unsure of the exact motherboard model, you can use the System Information tool: press Windows + R, type msinfo32 In the window that opens, you'll see the manufacturer and model. With that information, going to the official website and downloading the correct drivers is a piece of cake.

Another lever for improvement lies in the energy profile, Especially in portableIf you're working on battery power and the power plan is set to power saving mode, Windows may limit both CPU and USB port performance. Connecting your computer to a power source and enabling a "maximum performance" power plan helps prevent backups from being hampered by an overly aggressive power saving mode.

Finally, when the unit is very full or has been in heavy use, it's a good idea forma tear with a suitable file systemIn Windows, NTFS is usually the most balanced option for disks and storage devices that you'll primarily use with this operating system. This is not only due to its performance but also its compatibility with permissions, large files, and verification tools.

How the file system (FAT32, exFAT, NTFS) influences things

The file system is the way information is organized on the drive, and it has a direct impact on both the speed as well as maximum file sizeUSB drives or memory cards often use FAT32 or exFAT to prioritize compatibility, but that comes with important nuances.

FAT32 is highly compatible with virtually any operating system or device, but it has one serious limitation: does not support individual files larger than 4 GBFurthermore, its performance with large volumes of data and many writes is not exactly brilliant, so it is increasingly considered an obsolete system for intensive work.

ExFAT was created precisely to alleviate this limitation, supporting much larger files and working better with large, portable drives. However, if you're going to be working almost exclusively with Windows, NTFS usually offers better performance.especially on mechanical disks and high-capacity drives where the file system makes a significant difference.

If you have a USB drive formatted as FAT32 and don't need it to work on very old or specialized devices, you can convert it to NTFS or exFAT. From the Symbol of the system with administrator privileges, there are commands , the convert E: /fs:ntfs o convert E: /fs:exfat (changing E: to the actual letter of your drive) that allow you to change the file system.

Sometimes this conversion can fail or not be ideal, and in those cases it's safer Back up the content to another site, format from the Explorer with the desired file system (NTFS or exFAT) and then copy the data back. The process is slightly slower the first time, but you gain stability and speed in subsequent transfers.

Background processes, antivirus software, and other performance "thieves"

Even with good hard drives and modern ports, a PC overloaded with background tasks can cause... Any transfer seems to go in slow motionWindows often launches processes on its own (updates, security scans, search indexing, etc.) that compete for CPU, RAM, and disk access.

The classic example is Windows Defender, which can be set to scan while you're copying hundreds of gigabytes to an external drive. Every file written passes through the antivirus real-time analysis engineThis reduces the effective copy speed, especially with small and numerous files.

If you are certain that the files you are going to copy are safe (for example, your copies of personal photos or already verified material), you can consider Temporarily disable real-time antivirus for that specific operation. However, it's important to reactivate it when you're finished, otherwise you'll leave the device unprotected.

It's also advisable to take a look at the Task Manager (Ctrl + Shift + Esc) To see what's currently consuming resources. If you see processes that are spiking disk, CPU, or memory usage unnecessarily, you can close them to free up space and improve the transfer speed.

Do not forget that Not all files copy equally wellA single file of several gigabytes typically makes much better use of the drive's bandwidth than thousands of files of just a few kilobytes. Each small file involves additional file system and positioning operations, which significantly reduces the "average" speed you see on screen.

Choosing the right USB port and source drive

Within the same computer, Not all USB ports are equivalent.In addition to version (2.0, 3.0, 3.1, USB-Cetc.), some ports are connected differently internally and may offer different power or effective performance, especially in desktop computers with multiple controllers.

A quick way to tell them apart is to look at the color: the USB 2.0 ports are usually blackUSB 3.0 and later ports tend to be blue and sometimes include the "SS" symbol (for SuperSpeed). Whenever possible, connect your external hard drives and fast flash drives to these ports to take advantage of their higher bandwidth.

If your team has USB-C or Thunderbolt ports And your external hard drive too; you'll most likely get the best performance by connecting them together. These standards allow for transfer rates far superior to those of classic USB, which is especially noticeable when moving large files or making massive backups.

On the other hand, not everything is about destiny: read speed of the source disk It matters too. If you copy from a very full, fragmented, or slow-sector HDD, you'll see speed spikes and drops, even when the destination is a fast SSD or a modern NAS.

In those situations, free up space on the source disk and do a full defragmentation (if it's an HDD and not an SSD) This helps make readings more sequential and stable. This reduces head movement and improves sustained speed, resulting in faster copies without sudden jumps.

Backups from NAS and network drives: where is the bottleneck?

When you move data between a NAS, a PC, and a USB driveThe network comes into play and becomes another potential limiting factor. Even if your external hard drive and computer are fast, the transfer speed can be throttled by the network connection between the NAS and the computer.

In a typical Gigabit Ethernet network, the maximum theoretical speed is 1 Gbps, which translates to about 100-110 MB/s under perfect conditionsThat's already less than what a good USB 3.0 can offer. If one of the devices is connected via Wi-Fi, things get even more complicated: the actual speed can drop significantly, and signal stability affects every peak and valley you see in the copy.

Therefore, if you want to get the most out of TeraCopy or any tool, ideally you should Everything involved is connected by cable And, if possible, copy directly from the PC or NAS to which the external drive is physically connected. Another option is transfer files quickly over the network using locally oriented tools, avoiding USB if the network is faster.

Therefore, if you want to get the most out of TeraCopy or any tool, ideally you should Everything involved is connected by cable And, if possible, copy directly from the PC or NAS to which the external drive is physically connected. Many NAS devices include USB ports precisely for this purpose: copying from the network to the USB drive without going through the computer.

In migrations between NAS devices with different file systems (for example, from EXT4 to Btrfs on Synology), the following also comes into play: data integrity verificationHere, TeraCopy and its testing and verification functions make a lot of sense if you're worried about the copy getting corrupted along the way.

TeraCopy's "test" option reads the source files and generates checksums without actually copying them, allowing you to detect damaged files or problematic sectors before initiating a bulk transfer. Then, the "verify" function compares the source and destination hashes, ensuring that what has arrived is exactly what was sent.

Manage multiple copies without killing your PC

Another fairly common mistake is launch many simultaneous copy processes thinking that this way everything will be over sooner. In practice, the opposite is usually true: the disk goes crazy jumping around, queues fight for bandwidth, and the total time skyrockets.

If you need to move a lot of folders or large files, it's usually more efficient copy them in reasonable blocks or even one by oneThis allows each process to finish before starting the next. It requires slightly more monitoring, but performance is generally better and reduces the risk of everything crashing mid-process.

On older machines or those with limited RAM, opening too many copy processes can cause the Windows Explorer may consume 100% of CPU or memoryIf this happens, the system becomes sluggish or even freezes, forcing you to restart and risking the loss of your data.

From the Task Manager you can monitor resource consumption associated with the Explorer and TeraCopy. If you see that they are at their limit, it is best not to continue adding more queues in parallel and let what is already being processed finish before adding new work.

In this context, TeraCopy has an advantage over Explorer because It manages queues and errors better.This allows you to pause, reorder, and retry without crashing the system. Even so, the golden rule remains the same: the more organized your workflow, the faster and more secure it will be.

Copy faster with TeraCopy: how it really works

TeraCopy was created precisely to fill the gap where Windows Explorer falls short. Its main objective is copy and move files faster and more reliablyalso offering much more information about what is happening at any given moment.

The program dynamically adjusts the read and write buffers To reduce disk seek times, it automatically switches between synchronous and asynchronous modes as needed. This is especially noticeable when working between different physical drives (for example, from an internal SSD to an external HDD), where TeraCopy can make better use of input/output than Explorer.

One of its strengths is the error managementIf a file encounters problems during copying, the program doesn't simply freeze: it attempts to retry several times, and if that fails, it marks the file as unsuccessful but continues with the rest of the queue. You can then review those specific cases without losing your entire session.

The interface is quite straightforward: you choose the source files, select the destination folder, and then choose whether you want to copy, move, test, verify, or even delete. The options for “Testing” and “Verifying” are key for those who need to ensure that the copies are bit by bit identical to the original.

Another practical detail is that It can be integrated into the Windows context menu and replace the standard copy/move functions in Explorer. This way you still use right-click as usual, but TeraCopy actually manages the transfers, with its performance and control advantages.

Checksum verification: when to use Test and Verify

If you work with backups, huge media collections, or critical work projects, it's not enough for the bar to reach 100%. What's really important is that the copied files are identical to the originals, without silent corruption or truncated data.

TeraCopy integrates a powerful checksums Compatible with more than a dozen algorithms, from classics like CRC32, MD5, and SHA1 to more modern and faster options like BLAKE3 and xxHash3. This allows you to check file by file that the content has not been altered.

The "Test" function is used to Check the status of the source files before copying themThe program reads them and calculates their hashes; if it finds read errors or inconsistencies, you can detect them without having moved anything to the destination yet, which is very useful when you suspect that the source disk may be corrupted.

For its part, “Verify” is used after the copyTeraCopy recalculates the hashes of the destination files and compares them to those of the source. If there's even the slightest difference, you'll know which file has been corrupted, allowing you to retry or recover it from another source before considering the copy complete.

In addition, the application allows Create and validate external checksum files in common formats (.md5, .sha, etc.), which is very useful if you're going to transfer data between different machines or want to document the integrity of a backup for third parties. You generate the checksum file along with the data, and anyone can later verify that everything is still intact.

File queue control and Pro version

The TeraCopy file list is much more than a simple list of names: it acts as detailed log and control panel of everything that happens during the transfer. There you can see the status of each file, its size, its hashes, and any errors or warnings.

Once a copy is finished, you can focus solely on the problematic elements without having to repeat the entire process. The program lets you retry only the failed attempts, skip some, or even remove them from the list if you decide they are not needed.

The Pro version unlocks advanced features such as manual editing of the listThe ability to create favorite destination folders and export reports in HTML or CSV format is a key feature. This last function is particularly useful in professional environments where you need to document that a backup was made and how it performed.

Rules can also be defined for automatically ignore certain types of files (temporaries, caches, intermediate copies…), so that your transfers focus on the truly important content, reducing noise and time.

All of this is supported by a more informative progress bar than usual, which includes a real-time speed graph and color-coded to distinguish between successful, failed, and skipped files. If you want to identify bottlenecks on the fly, this view is far more useful than the standard Windows copy window.

Other utilities for faster copying (Ultracopier, FastCopy…)

Although TeraCopy is one of the most popular tools, it is not the only option for speed up or better control copiesDepending on your tastes and needs, another interface or a different approach might suit you better.

Ultracopier, for example, is an alternative focused on Improve the copying experience compared to ExplorerIt includes pause, resume, and error handling options. There's a fully functional free version and a paid edition with extra features. Its visual design is quite similar to the native Windows dialog box, although some icons might seem unintuitive the first time you use it.

Fast File Copy is committed to a two-column interface similar to a dual-pane file managerIt allows you to open multiple directories at once and copy by dragging and dropping in a very visual way. It's simple and convenient for those who prefer working with this layout, although its appearance is somewhat classic.

Copy Handler is a solution for open source and highly configurable For Windows. It offers filters, task queues, pause and resume functionality, and a large number of adjustable parameters. It shines especially on older versions of the system, where it can make a bigger difference, but its dense interface might intimidate less advanced users.

CopyMastro, for its part, is geared towards fast backups and synchronizationIt has a portable version for use on a USB drive. It allows you to maintain dates and permissions, apply filters based on criteria such as modification date or size, and verify integrity upon completion. It's a practical alternative to command-line tools for copy and sync filesAlthough its main drawback is a somewhat unintuitive interface and the fact that it hasn't been updated in a while, it still works well.

FastCopy, of Japanese origin, is considered by many to be one of the fastest and most efficient tools For copying on Windows. It handles files with very long names superbly, has detailed filters, and integrates into the context menu. Its design is spartan, but entirely focused on performance for users who value speed over appearance.

Alternatives when copying to USB is a nightmare

There are times when, no matter how much you optimize, Copying to a USB drive is not feasibleConstant errors, ridiculously slow speeds, or devices that start showing signs of failure. In these cases, it's best to consider other options instead of continuing to struggle with the same problem.

One of the most convenient alternatives is to resort to the cloud (Google Drive, Dropbox, OneDrive, etc.)If you have a good connection, you can upload your files to an online storage service and, from there, download them wherever you need them or share them via links, without depending on a troublesome USB drive.

Another practical option is to take advantage of the local network (LAN)If you have multiple computers at home or in the office, you can share folders between them and transfer files directly over Wi-Fi or, even better, via cable. For large volumes, an internal Gigabit network usually offers a better experience than constantly uploading and downloading from the cloud.

If what frustrates you is the fragility and slowness of some USB drives, perhaps it's time to make the switch to a external hard drive or portable SSDThese devices offer greater capacity, are usually more reliable, and, when connected via USB 3 or USB-C, achieve transfer rates far superior to most conventional USB drives.

When it comes to something urgent or sharing specific files with someone else, you also have simple services like WeTransfer or Send AnywhereThese tools generate temporary links for sending data without requiring registration or any heavy installation. They don't replace a good backup system, but they can be a lifesaver in a pinch.

With a sensible combination of good hardware, a finely tuned Windows configuration, and the support of specialized utilities like TeraCopy, it's perfectly possible. Accelerate and verify large file transfers without suffering crashes, without losing integrity along the way, and without having to watch the progress bar every minute.