What is the difference in size between a 2.5" external hard drive and a 3.5" external hard drive?

Question

i know a 2.5" drive can be easily held in a hard and is very portable, but can the same be said of the 3.5" hard drive. What would the average dimensions be of either?

Answer 1

well one is bigger than the other and the 2.5" hard drive is more expensive but apart form that there is not much more difference than that

Answer 2

Most of the 2.5" external hard drives are meant to be highly portable without taking up much space. The hard drive inside is actually a drive designed for use in laptops. In most cases the maximum storage capacity for 2.5" drives is 200GB. Most of the external dimension of the portable versions are about 3"x6" at approximately 1/2" thick.

3.5" drives are the type commonly used in desktop computers. They come with a variety of options, depending on which type of form factor you choose. One key advantage of 3.5" drives is storage capacity. There are currently external drives in the 3.5" size with storage capacity of 1TB, or 5 times the largest 2.5" drive. External dimensions tend to be bigger, usually around 5"x8" and about 1-1/2" thick.

Answer 3

A 2.5 inch external hard drive is based on a laptop drive. The external dimensions will be in the neighborhood of 3.5"x5.0"x1.0", or a bit larger than a pack of cigarettes. The major advantage of it is that you can build it to run off the power supplied by the USB bus, which means that you can build it without a separate power adapter. However, the downside is that it has limits on the capacity of the drive. The largest I have seen so far has been 160gb. The 3.5" external drive is based on a desktop drive and is about the size of a paperback book-call it 4.5"x6.0"x1.5". It has to have a separate power supply, but I have seen them as large as 750gb. They also will cost considerably less per gigabyte of storage than the 2.5" drives.

Answer 4

2.5" are generally used in laptops and cost more then 3.5", which are generally used in PC's. Both can be used as external drives.

# Physical size, usually quoted in inches:

* Almost all hard disks today are of either the 3.5" or 2.5" varieties, used in desktops and laptops, respectively. 2.5" disks are usually slower and have less capacity, but use less power and are more tolerant of movement. However, as of early 2007, manufacturers have started selling SATA and SAS 2.5" drives for use in servers and desktops.
* An increasingly common size is the 1.8" ATA-7 LIF form factor used inside digital audio players and subnotebooks, which provide up to 100GB storage capacity at low power consumption and are highly shock-resistant. A previous 1.8" hard disk standard exists, for 2-5GB sized disks that fit directly into PCMCIA or Cardbus expansion slots. From these, the smaller 1" form factor was evolved, which is designed to fit the dimensions of CF Type II, which is also usually used as storage for portable devices including digital cameras. 1" was a de facto form factor led by IBM's Microdrive, but is now generically called 1" due to other manufacturers producing similar products. There is also a 0.85" form factor produced by Toshiba for use in mobile phones and similar applications, including SD/MMC slot compatible hard disks optimized for video storage on 4G handsets. http://en.wikipedia.org/wiki/Hard_disk

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Make it a great day!

Answer 5

Apart from the obvious (one is bigger than the other) the 2.5" are used in laptops. The way they perform is exactly the same but I imagine that there is a price advantage with the 3.5". Why is it that small is always expensive - except when it comes to ones manhood!

Answer 6

The numbers refer to the physical size of the platters inside the housing. The larger the platters the larger the housing. My 3.5" externel is about 6" high by 8" long and about 1-1/4" thick.:-)=

Answer 7

The one thing nobody has mentioned is that 3.5 inch will require an additional power source whereas a 2.5 inch will not and can draw its power from the usb lead.

Answer 8

my 3.5" external floppy drive is about 4" x 5" x 0.5" (10cm x 12.5cm x 1.75cm) it's very portable, very light and just plugs into a USB port without instalation of software.

I've never heard or seen a 2.5" drive, most people use memory sticks now as they hold alot, they are cheep and small.

Answer 9

2.5" are those used in laptops.
3.5" are those used in desktops

The real issue is what you really need, size or performance???

2.5 are limited in size and speed. 120gb & 7200rm is typical max

3.5 will, generally, be faster and have more capacity. Not uncommon to reach 300 to 500gb, 10k or 15k rpm, etc.

So the real question is what do you need, physical size or drive capacity?

Answer 10

3.5" drives were named that because they were originally designed to fit in 3.5" floppy disk drive bays.

Standard 3.5" drive dimensions:
Form Factor Width (in) Depth (in) Height (in) Application
3.5" Half-Height 4.0 5.75 1.63 High-end, high-capacity drives
3.5" Low-Profile 4.0 5.75 1.0 Industry standard, most common form factor for PC hard disks

2.5" drive form factors are named after the size of the disk platters. (The actual spinning magnetic discs inside the drives.)

Standard 2.5" drive dimensions:
Form Factor Width (in) Depth (in) Height (in) Application
2.5" 19 mm Height 2.75 3.94 0.75 Highest-capacity 2.5" drives, used in full-featured laptop systems
2.5" 17 mm Height 2.75 3.94 0.67 Mid-range capacity drives used in some laptop systems
2.5" 12.5 mm Height 2.75 3.94 0.49 Low-capacity drives used in small laptops (subnotebooks)
2.5" 9.5 mm Height 2.75 3.94 0.37 Lowest-capacity drives used in very small laptops (mini-subnotebooks)

Info borrowed from here:
http://www.pcguide.com/ref/hdd/op/form_Trays.htm