Hard Drive Enclosures

Slowest to Fastest Interface:

 USB 1 , USB 2, Firewire 400, Firewire 800, IDE, eSATA


Vantec Single-Drive USB 2.0 Enclosure
They make these for IDE and SATA drives
with USB, Firewire, or eSATA ports
Visually stunning (in Red and Black also) - I own two of these
 
Mapower 5-Drive Enclosure
comes in 2, 3, 4, or 5 bays

VANTEC Nextstar 3 back panel - with USB 2.0 and eSATA (external SATA) Interfaces
 

CoolDrives 1394b Dual IDE Drive Enclosure - Firewire 800, Dual Fan, RAID 0 controller inside
The smallest dual-drive enclosure out there - just 2.5 inches thick !!
(I bought this unit - then realized the 2nd Firewire 800 port is only for Daisy Chaining
to another unit, so returned it !!  You cannot access the two drives
separately with two separate Firewire cables - so get two "Toughdrives instead (see below))

 

The "Toughdrive 800" single drive enclosure
with one IDE Drive, one firewire 800 port, and one USB 2.0 port
the fastest protocol for external drives, by far  .  .  .  is Firewire 800

 

*** also see "Go External" - an article on Firewire 800
       and our own pages on USB  and  Firewire

A hard drive enclosure is nothing more than a little box that you put one or more hard drives into.  Most of them have basic conversion adapters so that you can use a USB or Firewire cable to connect the drives to your PC.

These are not only extremely popular - but they should be considered mandatory for any serious computer user.

Are they Bottlenecks?  It depends  .  .  .

Running external drives on either USB or Firewire can create an instant bottleneck, if you use the external drive for high-speed applications !!  This is why:

USB 2.0 and Firewire 400 external drives are used primarily for data backup or apps that do not require high speed data transfer.

 Firewire 400 (1394a) limits throughput to 37 to 40 Mbytes/sec, which is slower than today's drive.  So it is the Firewire itself that becomes a bottleneck.  To get full speed a a fast drive in and out of your PC, you MUST use Firewire 800 !!  It is not possible for modern drives to equal the speed of Firewire 800 unless they are striped (RAID 0).

Firewire 800 drives are fast enough to run anything from - even video applications

You must understand that these protocols are rates in "bit per sec", while IDE and SATA specs are rated in "byte per sec".  Looking at the old, ancient ATA-33 IDE hard drive for example - it will transfer 33 MBps (Mega-Bytes per sec).  There are 8 bits in one Byte, so this is = 8 x 33 = 264 Mbps (Mega-bits per sec).  The recent ATA-133 is 8 x 133 = 1064 Mbps.  Far above the 400 to 480 Mbps of USB 2 and Firewire.  Bottom line, your hard drive is capable of much faster speeds than these cabling systems can supply.

  eSATA SATA 300 PATA 133 FireWire 800 FireWire 400 USB 2.0 Ultra-320 SCSI
Speed (Mbit/s) 2400 2400 1064 786 400 480 2560
Max. cable length (m) 2 1 0.46 4.5 (16 cables can be
daisy chained up to 72 m)		 4.5 (16 cables can be
daisy chained up to 72 m)		 5 (USB hubs can be
daisy chained up to 25 m)		 12
Power cable required Yes Yes Yes No No Yes/No USB 2.0 supplies +5 volts and will power 2.5" external disks (using two ports, unless the port offers more than the required current) or 1.8" disks (with a single port); other disks requiring more power will not function Yes
Devices per Channel 1 (15 with port multiplier) 1 per line 2 63 63 127 16

 

Enclosures vs Ready-made External Drives

You can add your own drive or drives to an enclosure, or you can buy a ready-made drive/enclosure unit, which typically contain two drives and allows you to run them in RAID0 or RAID 1 configurations.  The problem is - they do NOT usually have two ports for users who want to access the drives separately !!

The advantage is a clean solution, with RAID, that comes with everything, all assembled.  The Maxtor One-Touch III Turbo comes in 500 GB, 1 TB, and even 1.5 TB capacities, and is the most popular of these units.  Lacie also makes several popular and less expensive ready-made mega drives.

However - most modern motherboards come with RAID controllers that you can configure in the system BIOS - so if it is RAID you are after, then all you need is two drives - and a standard since enclosure that holds two drives, or two single-drive enclosures. 

eSATA - the fastest of ALL

Initially SATA was designed as an internal or inside-the-box interface technology, bringing improved performance and new features to internal PC or consumer storage. Creative designers quickly realized the innovative interface could reliably be expanded outside the PC, bringing the same performance and features to external storage needs instead of relying on USB or 1394 interfaces. Called external SATA or eSATA, customers can now utilize shielded cable lengths up to 2 meters outside the PC to take advantage of the benefits the SATA interface brings to storage. SATA is now out of the box as an external standard, with specifically defined cables, connectors, and signal requirements released as new standards in mid-2004. eSATA provides more performance than existing solutions and is hot pluggable.

  • Key benefits of eSATA:Up to 6 times faster than existing external storage solutions: USB 2.0, & 1394a
  • Robust and user friendly external connection
  • High performance, cost effective expansion storage
  • Up to 2 meter shielded cables and connectors

Using IDE Instead - the 2nd fastest possible Method !!!

This method is identical to using internal hard drives - you simply run the standard cables outside of your PC !!  You will need an extra IDE connector on your motherboard, and then you can run IDE cables out to an IDE enclosure.  There are not a lot of these out there, but Mapower makes them.  It will be the fastest and simplest of all, since there is no conversion from IDE to another protocol (such as USB or Firewire).  The flat ribbon cables are ugly and cumbersome - there fore if you do this, use the round IDE cables, and make a small cutout at the bottom edge of your computer cover to run the cable through.

SATA SATA SATA - so many are SATA !!

As you search for an enclosure, especially the dual-enclosures (2 drives), you will find the vast majority are for SATA drives only - it is very frustrating since the best looking ones are the newest models, and they all seem to be for SATA drives.  But as you know there are billions of perfectly good IDE (PATA) drives in existence, and in fact they make the best backup drives since they are cheap. 

USB vs Firewire

My own Tests

I copied 750 MB consisting of tons of files (the WinXP CD files store on my hard drive) - from external IDE Hard drive on USB 2.0 to my Internal Hard Drive on a Pentium 4, 3.6 Gbps machine.  Both are fast, IDE, 7500 rpm drives:

Internal IDE <---> Internal IDE :  45 secs (about the same in BOTH directions)

USB 2.0 external IDE drive <---> Internal IDE drive :    have not done this test yet

Firewire external drive <---> Internal IDE Drive :   have not done this test yet

*** USB 2.0 is rated faster than Firewire 400, but Firewire 400 is actually slightly faster -  and Firewire 800 is much faster

*** USB 2.0 is much slower than Firewire 800  !!  Firewire 800 is the king of external drive cabling !!

Both USB 2 and Firewire 400 are fast enough for backup drives !! 
If you have USB 2 and Firewire 400, use either. 
If you have USB 2 and Firewire 800 - use Firewire 800 !!

*** Firewire 800 enclosures are still rare, as are Firewire 800 ports
Here's are a few:

Let us review the specs:

Version Data Rate Max Cable Length ** Max # of Devices Comments
USB 1.0 1.5 Mbps ("Low speed") 3 meters 127 too slow for external hard drives !!
USB 1.1 12* Mbps ("Full speed") 5 meters 127 too slow for external hard drives !!
USB 2.0 1.5, 12*, and 480 Mbps
(480 M is "High Speed")		 5 meters 127 Backwards compatible with USB 1.0 and 1.1
Firewire 400
IEEE 1394		 400 Mbps 4.5 meters 63 up to 16 cables can be daisy chained using active repeaters, external hubs, or internal hubs often present in FireWire equipment.
Firewire 800
IEEE 1394b		 800 Mbps 4.5 meters 63 up to 16 cables can be daisy chained using active repeaters, external hubs, or internal hubs often present in FireWire equipment.

* for the 12 Mbps data rate limit - manufacturers quote only 11 Mbps - apparently the data is not reliable at 12 Mbps
** low speed devices have a max cable distance of 3 meters

Read and write tests to the same IDE hard drive connected using FireWire 400 and USB 2.0 show:

Read Test:

 Write Test: