Speed of saving to internal hard disk vs USB 3.0/2.0 external disk?

[pcwin]

If I am saving a backup to internal hard disk vs USB 3.0/2.0 USB external hard disk

1. Backing up to an internal 3.5 hard disk vs backing up to an external 2.5 hard disk using USB 3.0, roughly how much extra time would the external backup need to complete the backup process?

2. Backing up to an internal 3.5 hard disk vs backing up to an external 2.5 hard disk using USB 2.0, roughly how much extra time would the external backup need to complete the backup process?

Thanks

 

[Boozad]

There's no definitive answer, it would all depend on which internal drives you had (SSD/HDD, SATA 6GB, SATA 3GB) and which external drives you had and their relative transfer speeds. It's all just guesswork without that info.

 

[ignatzatsonic]

Backup from one standard internal to another is a LOT quicker than backup to any external that has to navigate through a USB port, whether USB 2.0 or USB 3.0.

How much will vary as Boozad says, but even a "slow" internal will receive files faster than an external.

I don't use external hard drives, but I do backup from internal to internal and from internal to USB flash drives.

Here are some of my own figures--I keep track of this in a Word file so I can compare drives over time.

Drag and drop D drive from Samsung 1 TB drive to WD Green 1.5 TB drive; both internal: about 72,000 files totaling 486 GB in 183.5 minutes. 2.65 gigs per minute. This is 159 GB per hour or 23 seconds per GB.

Drag and drop D drive from Samsung 1 TB internal drive to WD 640 GB in an external dock, via eSATA: 575 GB (about 89,000 files) in 158 minutes; about 3.6 GB per minute aka 218 GB per hour aka 16.5 seconds per GB, about 40% faster than the above drag and drop from internal to internal.

Drag and drop to 8 GB USB 2.0 thumb drive from WD Green 1.5 TB, backing up 15120 files totaling 3.93 GB through USB 2.0 port: 79 minutes aka 20 minutes per GB. Average file size 260k.

Drag and drop to 16 GB USB 3.0 thumb drive from WD Green 1.5 TB backing up the same 15120 files and folders, through USB 3.0 port: 16 minutes aka 4 minutes per GB.

Flash drive speed varies dramatically between brands and models--more than hard drives. The flash drives I used in both tests were cheap Kingstons. USB 2.0 versus USB 3.0 varied by a factor of 5 (20 minutes to 4 minutes). But copying from internal to internal was 10 times as fast as from the internal to the USB 3.0 flash drive.

I'm not sure of the relative speed of a typical USB flash drive compared to a typical external hard drive when they are connected through the same port.

Tough to make generalizations. File size, disk rpm, disk density, NAND type, external interface, and controller all come into play.