How to Speed up a Mac with External Storage
08 9月, 2025
Whether you’re a creative professional pushing pixels in Final Cut Pro or a remote worker juggling massive project files, the internal storage of your Mac® can only take you so far. That’s where external solid-state drives (SSDs) and external hard drives come in. These powerful storage tools don’t just expand your storage, they can significantly improve your Mac’s speed, responsiveness, and overall performance. In this post, we’ll break down how using external storage can transform your workflow, enhance file management, and even extend the life of your Mac desktop or laptop.
Even the most powerful Mac desktops and laptops can run into storage-related performance issues, especially as your workflow grows more demanding. Storage bottlenecks occur when your Mac’s internal drive struggles to keep up with the data being read, written, or transferred. This is most common with high-resolution media, large project files, or applications that require frequent access to large datasets, such as video editing, 3D modeling, and software development.
Many Mac users rely on SSDs built into their machines, which are fast but often limited in capacity. When these drives get close to full, macOS can’t operate as efficiently. System resources like virtual memory and background processes rely on free disk space to function smoothly. A nearly full drive leads to sluggish performance, longer load times, and even system crashes.
Another issue is some older Macs still use old drives which drastically limits throughput compared to modern NVMe SSDs. Without enough speed, apps that depend on real-time data access, such as Adobe® Premiere Pro or Logic Pro, can lag or freeze under pressure.
Recognizing storage as a potential performance choke point is the first step. Expanding your storage by using external SSDs or high-speed hard drives can alleviate these issues, offering both speed and space to keep your Mac running at its full potential.
A nearly full SSD slows down your Mac because of how both SSDs and macOS manage space for system operations. Here's a breakdown of why this happens:
MacOS relies on free disk space for:
SSDs work differently than hard drives:
While SSDs don’t suffer from fragmentation like hard drives, internal fragmentation can still affect performance if there’s insufficient contiguous space for large files or system operations. In short, a full SSD leaves the system with less room to ‘breathe,’ reducing its ability to manage memory, optimize storage, and run smoothly. Keeping at least 10–20% of your SSD storage capacity free helps maintain optimal Mac performance.
An external hard drive or external SSD can boost your Mac device’s performance in a few different ways:
MacOS requires free space on your internal SSD to run efficiently. When space gets tight (especially below 10–15%), your Mac has less room for:
By offloading large files like photo libraries, video archives, games, or older projects to an external drive, you reduce pressure on your internal SSD. This alone can lead to noticeable speed improvements across macOS, from faster app launches to smoother multitasking.
Modern external SSDs—especially ones using Thunderbolt 3/4 or USB 3.2/USB-C—offer incredibly fast read/write speeds, which are sometimes faster than the internal storage of older Macs. You can:
Because the external SSD can be just as fast or faster than your internal drive, this doesn’t hurt performance and often improves it, especially during file-intensive operations.
Many professional apps (like Adobe Photoshop, Premiere Pro, or DaVinci Resolve) allow you to assign a scratch disk, which is a dedicated space where temporary files are created during processing. Assigning an external SSD as your scratch disk helps:
This setup prevents your system from slowing down when juggling large temporary files, keeping creative workflows fluid.
If your internal SSD is:
You can install macOS on an external SSD and boot from it. With a fast NVMe SSD and Thunderbolt or USB-C, this creates a high-performance, portable operating system. You essentially give your Mac a second life:
To summarize things, an external drive doesn’t just add more space, it unlocks system performance by reducing internal storage pressure, supporting high-speed workflows, and even replacing underperforming internal drives. With the right setup, an external SSD becomes an essential performance tool for Mac users, especially creatives, developers, and power users.
Before investing in better hardware, a quick declutter can restore a surprising amount of speed to macOS. Here’s a straightforward, three-step workflow that pairs cleanup with an external Seagate drive:
| Step | What to Do | Why It Matters |
|---|---|---|
| 1. Audit the Space Hogs | Open > About This Mac > Storage > Manage…and sort by size. Focus on video exports, game installs, and obsolete Time Machine snapshots. |
Anything pushing the internal SSD past ~80 % capacity will slow read/write speeds dramatically. |
| 2. Offload, Don’t Delete | Drag-and-drop bulky folders—Steam libraries, Lightroom catalogs, completed project files—onto a formatted FireCuda® or Ultra Touch drive. Use macOS’s Move option so they’re removed from the source disk. |
You regain gigabytes instantly without losing access. USB 3.2 Gen 2x2 or Thunderbolt keeps the files just a few seconds away. |
| 3. Automate the Hand-Off | In System Settings > General > Storage, enable Optimize Mac Storage and set default export locations (Logic, Premiere, Photos) to the external drive. | Future assets land off-disk by default, preventing the creep that made your MacBook slow in the first place. |
Pro tip: Keep frequently used apps on the internal SSD for fastest launches, but store ancillary game DLC, raw footage, and completed renders externally. This hybrid approach mirrors the flex tier strategy data centers use, maximizing speed where it matters and mass capacity where it doesn’t. By reclaiming internal headroom and rerouting new data to high-performance external storage, you’ll notice quicker spotlight searches, shorter boot times, and smoother multitasking, proof a tidy drive truly is a faster drive.
When it comes to expanding your Mac’s capabilities, Seagate offers a range of the best external drives for Macs designed to match both the performance and aesthetic of Apple® devices. Whether you need high-speed SSDs for video editing, spacious hard drives for backups, or rugged options for work on the go, Seagate has a Mac-compatible drive to fit your workflow. In this section, we’ll explore the standout features of Seagate Mac-ready drives and how they can enhance your productivity, reliability, and storage efficiency.
For those who need more digital storage space and are looking to supplement the internal SSD on their Mac without breaking the bank, we recommend the Seagate Ultra Touch external hard drive.
The Ultra Touch is a solid all-rounder hard drive with:
The Ultra Touch is an excellent choice if price is your primary concern or if you intend to use the external drive for storing files and apps to free up space on your mac device.
FireCuda gaming SSD is the ideal solution for managing ballooning game download sizes and meeting the increasing demands for transfer and processing speeds.
While some Macs with internal SSDs can reach speeds of 5 to 7GB/s, upgrading that internal storage is often impractical. Opening up a Mac can be risky, technically challenging, and in many cases, voids the warranty. In fact, on most modern Macs, especially MacBooks with Apple silicon, the SSD is soldered onto the motherboard, making upgrades impossible after purchase.
For users looking to expand storage without opening their device, the Seagate FireCuda gaming SSD presents a fast and convenient solution. Utilizing a USB 3.2 Gen 2x2 interface, it offers speeds of up to 2,000MB/s, which is more than sufficient for quickly loading large game files, launching apps, or transferring media. With capacities of up to 2TB, it provides generous space for your games, creative projects, and media libraries, all while maintaining speed and reliability.
Our premium recommendation is designed to meet the needs of those who expect maximum performance from their external storage.
The LaCie® Rugged SSD Pro5 has it all:
Beyond those core performance specs, the LaCie Rugged SSD Pro5 is durable to a fault. IP68 water resistance rating. Withstands drops of up to three meters. Tough enough to handle being run over by a two-ton vehicle. It’s even built with at least 45% recycled materials, so you can rest easy knowing you’re helping reduce e-waste.
This is the SSD for you if you work with large file sizes in a professional setting and often find yourself on the go. And if you’re using a slightly older MacBook model, we have LaCie Rugged models that are compatible with previous generations of Thunderbolt ports as well.
Most of the process of setting up an external drive will be the same for a Mac as it would be for any other operating system. Plug in the peripheral, boot the appropriate program, and format the drive. There are two differences worth noting:
The second is harder to answer because formats get complex, and some names refer to overlapping definitions.
Here’s an overview of the format types you might see as you look stuff up online:
To use a Seagate external hard drive or SSD with your Mac, simply connect it via USB-C or USB-A (with an adapter if needed). Most drives formatted in exFAT or HFS+ will work right away, but if the drive is formatted for Windows (NTFS), you’ll need to reformat it using Disk Utility by choosing APFS for SSDs, Mac OS Extended (Journaled) for hard drives, or exFAT for cross-platform use. Once formatted, the drive will mount automatically, allowing you to store files, use it with Time Machine, or manage media. Always eject the drive safely before unplugging.
Here is the step-by-step process to setup your external drive with your Mac device and optimize your Mac device:
Offloading apps and content to keep the internal SSD below 80% capacity allows the SSD to operate at full performance.
Complete these steps once, and your Mac will recognize the external drive automatically every time, ready for faster loads, smoother edits, and hassle-free backups.
External SSDs are ideal for individuals working with high-resolution video, such as 4K, 6K, or 8K footage, or dealing with larger, more complex files. Their fast read/write speeds help prevent performance bottlenecks during editing, rendering, or scrubbing through timelines. If you plan to access files frequently or run apps like Final Cut Pro or Adobe Premiere Pro, an external SSD will offer a smoother experience.
Modern video files are large and data-intensive, so working from an SSD helps offload strain from your Mac’s internal storage, especially if it's limited in capacity. Some creators even run creative applications or entire projects directly from external SSDs, freeing up space and boosting overall system responsiveness.
That said, it’s good practice to minimize constant editing directly on any drive, especially SSDs. All drives, hard drives and SSDs alike, have a finite lifespan based on usage, particularly the number of read/write cycles. For active projects, working from fast external storage is fine, but maintaining a structured workflow with regular backups and archival strategies helps extend the life of your hardware and protect your data.
The three most common issues you might have with an external Mac drive are:
For problems like these, and many more, Seagate diagnostic tools can help with troubleshooting, and our support teams can assist you in solving issues that might otherwise be beyond your expertise.
To address formatting concerns, you first need to verify your drive’s format against the device type. Certain devices can’t support certain formats at all, so don’t waste your time shoving a square peg through a round hole.
You’ll either want to reformat the drive to something more compatible or plug it into compatible devices.
If you’ve checked the format and everything indicates it should be compatible, you may still need to perform some troubleshooting and possibly use additional software to complete the process.
Setting aside the fact that different port types and generations can impact transfer speeds, there’s one major concern to watch out for: a proprietary connection format. Namely, Thunderbolt. They resemble USB-C ports and function similarly, but not when connected to incompatible hardware.
A Thunderbolt port on your external drive will need a matching Thunderbolt input on the device. The generation also has to be compatible. If the external drive uses a newer version than the computer, it won’t work.
Some drives require additional power to run. Usually, they will have a dedicated power input. In the past, these ports had distinct shapes that would prevent users from connecting the wrong power cables. These days, it’s common for devices to have a USB-C or Thunderbolt port for power supply purposes.
Which means, if your drive needs additional power, you need to make sure:
Adding an external SSD or high-performance hard drive is one of the most impactful ways to breathe new life into your Mac. Whether you’re dealing with slow startups, lagging apps, or sluggish file transfers, a high perfromance external drive can drastically improve overall performance, offering faster boot times, smoother multitasking, and enhanced reliability.
With trusted solutions from Seagate, you can take full control of your Mac’s speed and performance without needing a brand-new machine. It’s a simple, smart investment that delivers immediate results so you can focus on creating, working, and enjoying your Mac the way it was meant to be.
Find out how Seagate external SSDs and hard drives improve your Mac's performance.
