Quick Answers to Key Questions
There are a few potential downsides to using an external SSD:
– External SSDs can be more expensive per GB than internal drives. The enclosure and extra components add to the cost.
– External SSDs are powered by the USB port, which may limit performance compared to an internal drive. Bottlenecks can occur.
– There are compatibility considerations with older systems that may not support USB 3.0 speeds.
– External SSDs are portable and easier to steal than an internal drive. You must be careful with physical security.
– Heat dissipation may be worse in a small external enclosure, causing potential throttling.
– External power sources and cord cables add clutter and points of failure compared to internal drives.
Cost Differences Between External and Internal SSDs
One of the main downsides of an external SSD compared to an internal SSD is the higher cost per gigabyte. External SSDs come enclosed in a housing that provides the USB interface, controller, and other components necessary to connect and communicate with the computer. This enclosure and the extra electronics add to the total cost of the drive.
Internal SSDs designed for desktop computers and laptops do not need their own enclosure – they are designed to mount directly into an existing drive bay and connect via SATA. This reduces the complexity and some of the costs.
For example, a 1TB internal 2.5″ SATA III SSD may retail for around $80 to $100. A 1TB external SSD with a USB 3.0 enclosure and controller might retail for $130 to $150. The external drive costs around 30-50% more per GB compared to the internal version.
However, users pay a premium for the convenience and flexibility of the external drive that can work across many devices. Still, dollar for dollar, and GB for GB, internal drives are cheaper. This cost difference is the most significant downside when evaluating external versus internal SSDs.
Reasons for Cost Difference
Here are some specific reasons why external SSD drives have a cost premium over their internal counterparts:
– External Enclosure – This aluminum or plastic housing holds the SSD in place, protects it, and allows for easy portability.
– Enclosure Electronics – An external SSD needs a bridge controller board to convert SATA to USB and facilitate communication.
– Cables – External drives need a USB cable for connection. SSDs designed for internal installation do not.
– Power Components – External enclosures need electronics to draw power over USB. Internals can tap directly into SATA power cables.
– Assembly – It takes time and resources to properly assemble the external enclosure and install the SSD. Internals ship as ready-to-install components.
– Branding – External drive enclosures are branded and packaged for retail, which adds marketing costs.
– Profit Margins – More players take a profit cut on external drives through the manufacturing and retail chain.
– Convenience Factor – Users pay more for the flexibility, portability, and convenience of a plug-and-play external SSD compared to installing an internal drive themselves.
Cost Per Gigabyte Comparison
To compare the cost difference directly, here is an example price comparison of some 1TB drives from major manufacturers:
| Drive Type | Product | Price | Cost Per GB |
|---|---|---|---|
| Internal 2.5″ SATA SSD | Samsung 870 EVO | $99.99 | $0.10 |
| External SSD | Samsung T5 | $149.99 | $0.15 |
| Internal M.2 NVMe SSD | WD Black SN750 | $129.99 | $0.13 |
| External SSD | WD My Passport | $159.99 | $0.16 |
As you can see, the external SSD options are around 30-50% more expensive per GB compared to similar performing internal drives. The premium is lowest going from a 2.5″ SATA to external SATA, while more significant when comparing NVMe internals to external SSDs.
This price and value calculation may change based on sales and discounts, but generally, the external premium holds across brands, capacities, and form factors.
Potential Performance Bottlenecks
Another downside to an external SSD compared to an internal model is the potential for performance bottlenecks. While the latest USB interfaces like USB 3.2 Gen 2×2 can rival the speeds of internal SATA and even NVMe SSDs, in real-world use the USB interface can still be a limiting factor.
USB 3.2 Bandwidth Limits
USB 3.2 Gen 2×2 theoretically can reach transfer speeds up to 20 Gbps. Here is how that theoretical max speed compares to other SSD interface bandwidth limits:
– SATA III = 6 Gbps
– NVMe PCIe 3.0 x4 = 16 Gbps
– NVMe PCIe 4.0 x4 = 32 Gbps
As you can see, USB 3.2 Gen 2×2 has enough bandwidth on paper to handle the fastest SATA or PCIe 3.0 NVMe drives without bottlenecking. However, the practical speeds you’ll see externally will be lower than the internal drive’s rated specs in most situations.
Shared Bandwidth and Other Overheads
In practice, the USB interface has about 80-90% efficiency. After factoring in protocol overhead and the hub architecture with potential other shared devices, you’ll see lower usable transfer rates.
While an internal PCIe 4.0 SSD might reach sequential reads around 5,000 MB/s, externally over USB you could expect around 3,500 MB/s max under ideal conditions. So there is performance left on the table.
Other devices on the same bus can also impact portable SSD speeds. For example, using a multi-port hub to connect several USB drives will split the available bandwidth and create a bottleneck.
Compatibility and Cable Issues
Additional bottlenecks can occur if the USB host hardware can’t support the fastest Gen 2×2 transfer rate. Older laptops or mobos may be limited to 5 Gbps or 10 Gbps rates. Cables can also be a factor – a poor quality USB cable can choke speeds.
So while the USB interface itself and compatibility factors represent the main performance limiters, in practice even the fastest external SSD will see slower speeds than its potential internal SATA or PCIe counterpart.
Compatibility With Older Systems
To achieve the fastest speeds possible, an external SSD using a USB 3.2 Gen 2×2 or Thunderbolt 3/4 interface requires the host computer to have compatible ports and drivers. This can be a downside when trying to use an cutting-edge external SSD with an older system.
For example, a USB 3.2 Gen 2×2 SSD requires a USB-C port on the computer to achieve its maximum transfer rate. However, many older systems built before USB-C became commonplace only have USB 3.0 Type-A ports.
When you connect a high-speed external SSD to an older USB-A 3.0 port, transfer rates will be limited to the maximum of USB 3.0 – around 500 MB/s. The SSD itself may be capable of 2,000+ MB/s speeds, but the interface compatibility prevents those speeds from being reached.
This means you won’t be able to take full advantage of the latest and fastest external SSDs when using older systems lacking USB-C or Thunderbolt 3/4 ports. You would be paying for performance that can’t be used.
Solutions for Older Systems
If trying to use a cutting-edge external SSD on an older system, you do have some options to improve compatibility:
– Use adapter cables to connect the USB-C SSD to a USB-A port. This improves compatibility but limits speed.
– Install a USB 3.1 or 3.2 PCIe card add-in card to add faster USB ports to an older system.
– Upgrade to a newer system with native USB 3.2 Gen 2×2 or Thunderbolt support to unleash full SSD speeds.
– Use an external SSD with a slower interface like USB 3.0 to match the capabilities of the older system ports.
Regardless, you won’t see the full performance potential of the fastest external SSDs without more modern host hardware capabilities. This can make those SSDs a poor value proposition for older PCs.
Portability Increases Physical Theft Risks
The portable and compact nature of external SSDs brings an increased risk of device theft compared to a fixed internal drive. Their small size makes them easy to steal and conceal.
A desktop PC or locked server with internal drives is far less susceptible to physical theft compared to an external drive that can fit into a pocket or bag. And while internal drives can also be removed, it requires tools and removing case panels – an obvious case of theft.
But external SSDs can be quietly disconnected and stolen in just seconds, whether in the office, library, cafe, airport, or other public spaces. The USB cable provides a quick getaway.
This gives external SSDs a higher risk profile than internal drives in terms of physical security. Their portability becomes a disadvantage in the wrong hands. Proper cautions need to be taken to prevent device theft and data loss.
Precautions Against External SSD Theft
To help mitigate the risk of external SSD theft, consider following precautions:
– Avoid leaving drives on desks unattended, even briefly, in public spaces
– Keep external SSDs locked away or hidden out of sight when not in use
– Use drive encryption technologies like BitLocker to protect data if theft occurs
– Chain or lock external SSDs to desks with a cable lock as a deterrent
– Track drives with tagging devices like Apple AirTags to aid recovery
– Back up important data as a redundancy against drive theft
– Purchase external drives with fingerprint unlocking mechanisms for added security
With proper physical precautions, the portable nature of these drives can be protected against opportunistic theft. But extra vigilance is required compared to installed internal drives.
Potential for Overheating
The small, enclosed form factor of external SSD enclosures presents some potential challenges with heat dissipation and thermal throttling compared to internal drives.
Tight Spaces Limit Airflow
External enclosures trap heat from the SSD controller and NAND flash memory chips in a very tight space. The portability prioritizes miniaturization over airflow. And USB cables block any gaps that would allow airflow.
Internal SSDs in desktops have large PC cases with open space and multiple fans that provide active cooling. This allows heat to dissipate much easier from internal components.
The tight external SSD enclosure limits air circulation, causing heat to build up rapidly. This is problematic for performance – SSD controllers will throttle speeds to back off from overheating if temperatures rise too far.
Thermal Throttling Can Degrade Performance
Most external SSD controllers are designed to throttle if temperatures exceed 70°C to 80°C. Sustained reads or writes will cause overheating, and performance will drop sharply, with speeds degrading up to 50-70% in some cases.
Throttling typically occurs during transfers of very large files, like 20+ GB 4K video files. The SSD cannot cool off before overheating again, so speeds remain throttled.
While smaller file operations may not cause thermal limits to be reached, large transfers will commonly face throttling issues on many external SSD models, particularly under sustained maxed-out workloads.
This can degrade the user experience. Internal drives within actively cooled PC cases are less prone to overheating and thermal throttling issues during demanding workloads.
Solutions for Thermal Issues
There are some potential solutions if an external SSD model seems to be prone to overheating and thermal throttling:
– Use a laptop cooling pad or fan tray to actively cool the drive from underneath
– Opt for a larger capacity model – higher capacities often run cooler with the same workload
– Limit the concurrent workload on the drive to prevent maxing out temps
– Choose an aluminum-bodied enclosure option for better passive cooling
– Check for firmware updates that may improve thermal calibration
– Consider adding thermal pads if the enclosure allows users to open it
The compact external design prioritizes portability over heat dissipation. Some thermal compromises are inevitable. But steps can be taken to minimize overheating and maintain better performance.
Cables and Power Supplies Add Clutter
Another downside to external SSDs is the extra cables required to connect and power the drive through USB. This can add clutter and cable management challenges versus clean internal installations.
Cabling and Power Supply Requirements
External SSDs need a USB cable to connect to a PC, laptop, or mobile device to function. Bulkier desktop drives may require dual USB cables for sufficient power delivery. This can proliferate cabling.
External SSDs also rely on power delivery over that USB connection and do not have their own power supply. This means you cannot use most external SSDs without also connecting them to a powered USB host.
Compare this to internal SSDs that mount directly into a drive bay and get both data and power connections from interfaces within the PC case. No external cabling clutter is introduced.
Cable Trips and Clutter Drawbacks
From a user experience and convenience standpoint, cables are one of the bigger nuisances and disadvantages of external drives versus their internal counterparts:
– More cables to get tangled up in desk clutter or snag on objects
– Always need free USB ports to connect the SSD externally
– Can’t easily hide away cabling for clean setup like internal builds
– Adapters or hubs needed for laptops/devices with limited USB-A ports
– Extra power supply to carry if the SSD needs more power than your ports provide
While cables and connectivity needs are necessary compromises for the external form factor, they do create downsides compared to the direct SATA and PCIe connections of internal SSDs.
Potential for Damage and Disconnection
The cables connecting and powering external SSDs also introduce potential failure points and reliability concerns.
Accidentally pulling on a USB SSD cable can damage the port or cause physical harm if the drive crashes to the floor. Loose connector cables can disconnect during read/write operations, causing data errors or corruption.
External SSD cables are prone to fraying and mechanical wear over time, eventually leading to connectivity failures. Internal SSDs have lower risks of these cable-related issues due to directly soldered SATA or M.2 PCIe connections.
So cabling introduces not just clutter but fragility and failure points over time. Drives designed for permanent installation have the reliability edge.
Summary and Conclusion
While external SSDs provide excellent performance and conveniences, there are some downsides to consider when choosing external versus internal drive options:
– External SSDs have a higher cost per gigabyte in most cases due to the extra enclosure and components required. You’ll pay a premium over internal drives.
– Though fast, USB interfaces can bottleneck maximum speeds versus a direct PCIe or SATA internal connection. Other bottlenecks like shared bandwidth and older USB ports on a system create limitations as well.
– The physical portability of external SSDs increases risks of device theft if proper precautions aren’t taken. Internal drives mounted inside desktop cases are more physically secure.
– Tight external enclosures can contribute to overheating and thermal throttling during sustained workloads. Airflow is restricted compared to PC cases designed for cooling.
– External SSDs require additional cabling that can clutter workspaces and introduce points of failure over time as cables fray or connectors fail. Internals have no cabling issues.
For these reasons, external SSDs have some downsides to weigh against their significant convenience, portability and platform-agnostic advantages over internal drives. Understanding these trade-offs allows you to choose the right SSD solution for your specific needs and use cases.