Are external SSD faster than internal HDD? (Answer, Reasons)

SSDs and HDDs are both used simultaneously in a PC. They both have their advantages and none of them can be omitted when building a PC. But what if you want to use an external SSD and an internal HDD?

The performance of SSD is higher than HDD. But when you connect SSD externally with a USB port will it be faster than an HDD connected internally through a SATA cable? Let us understand which one is better and faster in this article.

Are external SSD faster than internal HDD

Are external SSD faster than internal HDD?

External SSDs are faster than Internal HDDs. But the speed of external SSD depends on the type of interface used and the speed of internal HDDs depends on the RPM of the drive. If the external SSDs use the latest USB tech, you may experience faster data transfer than internal HDDs. If the external SSDs use older gen USBs, then it will match the performance of internal HDDs.

We shall get into detail about the speed differences between the two and the reason behind the difference in performance.

Why external SSD is faster than internal HDD?

Generally, SSD technology is faster and more efficient than HDDs. Hard disks use mechanical drives which are not fast and can easily get damaged within a few years.

But an SSD uses NAND flash storage technology which can store data for years without any risks. The potential of an SSD is higher when compared to hard disks.

When it comes to external SSDs, they can only be connected through a USB interface. This USB is what limits the performance of the SSD. Although SSDs can transfer huge amounts of data within seconds, the USB interface limits the speed within its data transfer capacity.

For example, if an SSD can transfer 40Gb/s, USB 3.1 can transfer only up to 1.2 Gb/s. So, when this SSD is connected to the PC or Mac with a USB 3.1 connector, it can only transfer data with 1.2 Gb/s.

But the fact here is this speed of external SSD is way faster than the highest available internal HDD. Because the problem in internal HDDs is not the connector, but rather the mechanical drives of the HDD.

Every hard disk drive is connected using SATA cables. The latest SATA 3 can transfer 6Gb/s. But that is not the limiting factor here. The mechanical drives of the HDD can only function up to 7200RPM and this converts into just 80 to 160Mb/s.

Even though SATA connectors are capable of high data transfer rates, hard disk drives are not efficient enough to read or write at higher speeds.

That is why you can find the external SSDs to be faster than internal HDDs. At the same time, if you use a lower gen USB connector with external SSDs, then you can have a similar performance to internal HDDs.

To summarize we can say that the performance of external SSDs is limited by the connecting interface and the performance of internal HDDs is limited by the mechanical drives.

Read: Which is better hybrid drive or SSD?

Speed Differences between External SSDs vs Internal HDDs

Let us now look at the speed differences between external SSDs and internal HDDs so that you can understand them better.

SSD connected with different USB Transfer Speeds
USB 3.1 1.2Gb/s
USB 3.0 625Mb/s
USB 2.0 60Mb/s
Internal HDDs with different RPMs Transfer Speeds
15,000 RPM 160Mb/s
10,000 RPM 140Mb/s
7200 RPM 80-160Mb/s
5400 RPM 75Mb/s

Read: Why are Flash Drives slower than SSD?

If you look at the above tables, you can find that the performance of external SSDs is way higher than Internal HDDs. Even with higher RPM drives, the HDDs cannot match the performance of USB 3.0-enabled SSDs. The lowest available USB 2.0 SSDs match the performance of commonly found 5400 RPM HDDs. 

If the SSDs are connected using a Thunderbolt interface, then you can have a blazing-fast read speed of 2 Gb/s. This cannot be matched by the performance of HDDs ever. 

Therefore, external SSDs are faster than internal HDDs despite their connection interface. Even though HDDs are connected through SATA cables, it doesn’t affect the performance in a significant way.

Read: Solid State Drive vs Hard Drive

Pros of using SSD as External Storage

  • The apparent advantage of using SSDs as external storage is that they are faster and more efficient. 
  • The reliability of SSDs is higher because the chances of data corruption are less.
  • You can instantly read or write data with your external SSD.
  • The portability of external SSDs is way higher due to their compact size.
  • The efficiency of reading and writing is higher when compared to HDDs.
  • With USB 3.1 and Thunderbolt, you can have blazing-fast read/write speeds.
  • They are often lightweight and usually found in a thin form factor.
  • Many advanced technologies like fingerprint locks are being used in external SSDs.
  • If you are constantly moving around, then external SSDs are a great choice.

Read: How do SSD and HDD work together for PC?

Cons of using HDD as Internal Storage

  • HDDs are not reliable and can fail anytime due to the presence of mechanical parts.
  • They have a very less lifetime compared to SSD tech and can get corrupted soon.
  • The read and write speeds are way less when compared to SSDs.
  • They are not portable and are very bulky when compared to SSDs.
  • You have to go for higher RPM drives for faster read and write speeds.
  • Despite the use of SATA cables, they are slower than SSDs.

These are the disadvantages of using HDDs as internal storage devices. The only advantage of HDDs is that they are cheaper. Even 2TB or 3TB HDDs are easily affordable than a 500GB SSD. Therefore, in terms of speed and data transfer, SSDs are better whether they are internal or external.


Internal HDDs are popularly sought by many users due to their affordable large-capacity storage drives. But for performance, you have to go for SSDs whether internal or external. If you want a portable storage drive, then you must choose an external SSD and use it with your internal HDD. Combining these two will be a better choice that gives both performance and vast storage.

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