SATA (Serial ATA) and external hard drives are two common types of hard drives used for data storage. A SATA drive is an internal hard drive located inside a computer that connects to the system’s motherboard via a SATA interface. In contrast, an external hard drive is a portable data storage device that connects to a computer externally, typically via USB.
Both SATA and external hard drives store and retrieve digital data. However, there are some key differences between them in terms of speed, power, portability, capacity, cost, and use cases. This article will provide an overview and comparison of SATA and external hard drives to understand when each one might be the optimal choice.
What is a SATA Drive?
SATA stands for Serial ATA and it is the primary type of internal hard drive used in modern computers (https://en.wikipedia.org/wiki/SATA). SATA drives connect to the motherboard via SATA ports and cables. SATA succeeded the older Parallel ATA (PATA) standard and started being adopted by computer manufacturers in the early 2000s (https://www.techtarget.com/searchstorage/definition/Serial-ATA).
The main advantages of SATA over PATA are faster data transfer speeds, thinner cables that allow for better airflow in computer cases, and native hot swapping support. SATA has evolved over several revisions to increase maximum bandwidth from 150 MB/s in the initial 1.0 spec up to 16 GB/s in the latest SATA 3.0 version.
What is an External Hard Drive?
An external hard drive is a storage device that is external to a computer case and is not enclosed inside it. External hard drives typically connect to a computer through a USB, eSATA, or FireWire connection.
External hard drives first emerged in the early 1980s and were mainly used to back up internal hard drive data. As technology improved, their storage capacities increased while their physical size decreased. Today, external hard drives come in a wide range of storage sizes from 500GB to 10TB and higher.
Some of the notable benefits of external hard drives include:
- Portability – They can easily be disconnected and transported.
- Data security – Important files can be backed up offline.
- Storage expansion – They provide extra storage beyond the internal hard drive.
- File sharing – Files can easily be shared between computers.
Common uses for external hard drives are for backups, data archives, file storage/transfer and expanding storage beyond a computer’s internal hard drive. They continue to be a popular data storage solution for both personal and business use.[1]
Speed Comparison
In terms of max speeds, SATA drives have much higher theoretical speeds compared to USB drives. SATA I has a max speed of 1.5 Gb/s, SATA II is 3 Gb/s, and SATA III is 6 Gb/s. Meanwhile, USB 2.0 maxes out at 480 Mb/s, USB 3.0 at 5 Gb/s, and USB 3.1 Gen 2 (sometimes labeled USB 3.2) at 10 Gb/s.
However, real-world benchmarks show that actual performance can vary quite a bit from these maximums. According to testing by Flexense, a SATA III drive is on average about 30% faster than a comparable USB 3.0 drive for typical file operations. On Reddit, some users report SATA III outperforming USB 3.0 more substantially, though results depend heavily on factors like drive quality and workload.
So while SATA’s maximum speeds are much higher than USB, real-world use cases see a less dramatic but still noticeable performance advantage for SATA drives.
Power and Portability
One of the main advantages of external hard drives is their portability. External hard drives are powered independently, usually via a USB cable, so they don’t require a power connector from the computer like internal drives do. This makes external drives completely portable – they can easily be unplugged, transported, and plugged into any other computer. This comes in handy for transferring large files between computers or taking your data on the go.
However, the portability of external drives makes them more prone to physical damage from drops, impacts, liquid spills, etc. An internal drive installed inside a computer case is more protected. Overall, the portability and independence of external drives provides flexibility, but potentially less physical protection compared to internal drives.
According to Reddit users, external hard drives may fail more frequently than internal ones in part because they get bumped around and dropped more often while being transported [1].
Capacity
External hard drives today can offer massive storage capacities compared to older models. For example, external hard drives with up to 2TB of storage are commonly available from major brands like Western Digital and Seagate.
However, internal hard drives still tend to offer higher maximum capacities than external drives. Internal hard drives now go up to 20TB for consumer models and even higher for enterprise drives. This is because external hard drives are limited by the USB interface and the size constraints of being portable.
So while external hard drives today provide adequate storage for most home uses, professional users with very large storage requirements may still need to look at internal drives to get the absolute highest capacities.
Cost
In general, external hard drives tend to have a higher cost per gigabyte compared to internal SATA hard drives, according to Disk Prices (US). However, prices vary significantly based on the brand, features, and demand.
For example, a Seagate Expansion Desktop 14TB external hard drive costs around $0.018 per gigabyte, while an internal 14TB SATA drive averages around $0.014 per gigabyte according to Hard Drive Cost Per Gigabyte. High-end external drives from brands like LaCie can cost over $0.047 per gigabyte.
External drives often include protective casings, backup software, and additional connectivity options that increase their price. But lower-end external drives without extra features can have similar per-gigabyte costs as internal drives.
Ultimately, both SATA and external drives provide economical storage solutions. But external drives generally come at a small premium for their enhanced durability, portability, and ease of use.
Security
External hard drives can be more prone to physical security risks if the drive is lost or stolen compared to an internal SATA drive which stays inside a computer case. However, external drives also make it easier to keep backups offline and disconnected from the internet which is an advantage for data protection against remote hacks or malware (1). There are steps users can take to mitigate security risks of external drives like encrypting the drive, using strong passwords, maintaining physical control of the device, and properly disposing of drives when retired (2). While internal SATA drives have more physical security within a case, data on them is still vulnerable if the system is infected with malware or is hacked remotely.
Use Cases
Internal hard drives are usually preferable for desktop computers where portability is not a priority. Internals have faster read/write speeds since they connect directly to the motherboard via SATA without any external interface. This makes them better suited for tasks like installing operating systems, games, or running demanding software. However, for laptops and tasks where portability is key, external drives are a better choice.
External hard drives excel when you need to physically move data from one device to another or keep backups in a separate physical location. Their plug-and-play functionality lets you quickly connect the drive to access files. Portable externals with large capacities are great for transporting libraries of photos, videos, music, or other media. Rugged and durable external models can safely travel in harsh environments. Shared drives make it easy to collaborate, with some externals allowing multiple connections. Externals can also expand limited storage on laptops, games consoles, or media boxes.
In summary, internal drives are best for performance-driven desktop tasks, while externals are preferred for portability and transportation of large data sets across multiple systems.
Conclusion
In summary, SATA and external drives both have their advantages and drawbacks depending on your use case. SATA drives are best for installing internally in a desktop PC where speed, capacity, and cost savings are the priority. External drives excel at portability and plug-and-play use for storage, backup, or transferring files between computers.
If you need a speedy drive as your computer’s boot or program drive, a 3.5″ SATA III SSD is the way to go. For maxing out capacity for storage of large files like videos, 3.5″ SATA HDDs give you the most terabytes per dollar.
For external portable storage and backup, compact 2.5″ external SSDs offer quick file transfer speeds in a sturdy, shock-resistant package. Standard external HDDs provide more storage for less cost compared to SSDs. Wireless external drives free you from cords to stream and access files on multiple devices.
In the end, choosing between SATA or external drives depends on whether you value space savings, performance, expandable capacity, portability, or ease of access most for your needs and budget. Compare the pros and cons and plan your purchase accordingly. With the right storage solution, you can enjoy peace of mind knowing your data is safe, secure, and readily available when you need it.