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External hard drive vs homemade external hard drive

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  • Cases
  • Storage
  • Hard Drives
  • External Hard Drive
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May 26, 2014 8:18:45 AM

I havent got a harddrive, the case for it or something, so without anything from the beginning, what should i pick? A premade external harddrive(please refer to a good model) or something i make myself. What i could see as problems in both

Homemade - Might not be as safe to throw around everywhere, and might vibrate a whole lot on my desk.

Premade - Unable to swap out to a new drive if this one fails.

What should i pick? What is safest for storage, premade or homemade external hdd?

More about : external hard drive homemade external hard drive

a b G Storage
May 26, 2014 8:31:30 AM

Hi
Some retail external USB or esata hard drive cases can not easily be opened
And USB to sata bridge chip may be integrated into hard disk controller card, making emergency repairs more difficult & expensive

Are you going for 2.5" or 3.5" drives. .
3.5" will require a psu

Choose a good quality case and a good quality hard disk.

Since you normally get no cooling fan in a external drive a cool running slow speed hard disk may be better than the fastest drive available

Regards
Mike Barnes
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a c 363 G Storage
May 26, 2014 9:30:20 AM

By "homemade" I assume you mean assembling one from an external enclosure and a stock HDD unit.

I don't believe that premade ones are any more resistant to shock and vibration.

With homemade you can always replace either the enclosure or the HDD singly if there is a failure, or if you decide to upgrade to a larger HDD unit. Premade ones often make this more difficult.

Many premade models have application software included on them for automatic backup systems and other useful stuff - may be handy if you want what they give you. BUT many also have proprietary coding or security locks on the HDD, making replacement of the HDD unit or data recovery very difficult. Assembling from stock units avoids these latter issues.

It is true that an external unit containing a 3½" HDD unit (typical desktop HDD unit) inside will need a power supply module. That normally comes WITH the enclosure you buy to mount that HDD. Here's the power story background. Small 2½" HDD units for use in laptops are designed for very low power consumption with slower speeds and slightly slower performance. Often they can be mounted in an external enclosure designed for them such that the entire assembly can be powered completely by the USB2 port they are connected to. The same goes for premade "portable" external drives. A USB2 port can supply up to 0.5 amps current, and this is just sufficient to power external drives designed for that. Some external small-form-factor drive units are not quite so low on power requirements and come with a special cable with 2 USB2 connectors on its end. Both of these need to be plugged into USB2 ports to provide enough power. But when you get to 3½" form-factor HDD units typical of desktop machines, they ALL need more power than this, whether they be slower 5400 rpm units or faster 7200 rpm units. These cannot be powered solely from a USB port, and need their own power supply module. When you use that, no power is required from a USB port. NOTE that, if your connection system is NOT USB - that is, you use eSATA or Firewire - these ports normally do NOT have any power available, and you MUST have a power supply, no matter what type of HDD is inside.

It's true that many enclosures do not contain a cooling fan. Personally, I worry that a fan will wear out its bearings and need replacement, so I'd want one with a very common easily-replaceable fan. OR, as I have done, be happy without a fan! My enclosure has no fan, and I did NOT go for a low-power 5400 rpm "green" HDD inside, but it still operates at perfectly acceptable temperatures.

In choosing an external enclosure you need to pay attention especially to two interfaces:
1. The internal interface, between HDD and the enclosure, must accept the HDD type you want to use - maybe even have some options. Almost always today you'll need one for SATA, MAYBE for a small laptop-size (2½" form factor) SATA HDD. SATA II or III (more properly called SATA 3.0 Gb/s and SATA 6.0 Gb/s) does not matter - no spinning-disk mechanical HDD can deliver data faster that the older SATA 3.0 Gb/s standard.
2. The external interface, between the enclosure and the computer. In order of data transfer speed, they usually are USB2 (slowest), eSATA, IEEE1394a (Firewire 400) (these two comparable to internal SATA 3.0 Gb/s ports), IEEE 1394b (Firewire 800) and USB3 (both faster than HDD's can go; Firewire 800 not so common on PC's). Often you get an external unit (premade or enclosure) with more than one external interface, and you get to use only one at a time. Normally, only the two USB systems offer power in the port (USB3 more power than 2), although there are non-standard versions of eSATA that have power also.

Some time ago I made my own. I bought an external enclosure with no fan for a SATA II HDD, with eSATA and USB2 ports. I mounted in it a 500 GB SATA II HDD unit, 7200 rpm. I connect it to my computer's eSATA port, although I have used it rarely via its USB2 port to connect to other machines that did not have eSATA.

Here's a benefit of my do-it-myself unit. I use it for backups by making complete clones on it of both my internal HDD units, in separate Partitions. (Each of them is not very full.) My computer cannot BOOT from the eSATA port or a USB2 port. But I tested to make sure it could be a backup against disaster. I simply opened up the enclosure and removed the HDD unit (the reverse of installing it - simple!) and mounted it inside my computer, disconnecting the normal internal drives to simulate the recovery-after-disaster scenario. When switched on, the computer booted perfectly from the transplanted HDD containing the two clone images, and ALL my stuff was instantly available. After the test I just reverted to normal, transplanting the HDD back into its external enclosure. Such a process would be more difficult using a pre-made external HDD that is hard to open and disassemble, or that uses proprietary protection of the HDD unit.
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May 26, 2014 10:11:58 AM

mbarnes86 said:
Hi
Some retail external USB or esata hard drive cases can not easily be opened
And USB to sata bridge chip may be integrated into hard disk controller card, making emergency repairs more difficult & expensive

Are you going for 2.5" or 3.5" drives. .
3.5" will require a psu

Choose a good quality case and a good quality hard disk.

Since you normally get no cooling fan in a external drive a cool running slow speed hard disk may be better than the fastest drive available

Regards
Mike Barnes

I am going for 2.5" since i will be having it many places, storing stuff on it and backing things up to it.

7200rpm vs 5400rpm? I have seen 2.5" hdds 7200rpm be just fine without fan cooling in laptops(i was thinking seagate or WD)
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May 26, 2014 10:19:10 AM

Paperdoc - (i am not gonna quote that long reply) My use will be for backing up mostly, and storing random files. And then the limits of the usb2/3, if i were to put in a 2tb hdd into a usb3 enclosure, and accidently plug it into usb2.0 possibly starving it for power, would it kill the drive, or would it simply not start?

And i did not understand the last part - you backed up your whole computer with multiple harddrives inside it onto one external disk, then you recovered the pc to standards, while the other files were on the external drive, and you did a clean install? Wouldnt a usb flash drive be enough for that little recovery thing?

So at last, it comes down to compatibility of the diy external disks, and on the premade hdds, it comes down to - do i need to take it out?
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May 26, 2014 10:34:18 AM

1. I cant find a hdd enclosure that supports 15mm high hdds
2. 2tb 2.5" hdds are crazy expensive(compared to the premade)

I think i will go premade here, but thanks for trying to help me
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a c 363 G Storage
May 26, 2014 8:43:47 PM

Yeah, one common thing you'll find: a 2½" HDD is about twice as expensive as a 3½" HDD for the same storage capacity.

If you opt to make your own, check very carefully how much power is required for the HDD unit you want to use. A standard USB2 port supplies power at 5 VDC to a max of 500 mA - that's 2.5 Watts. On a USB3 standard port, that 5 VDC supply can provide up to 900 mA - that's 4.5 Watts. I'm not sure how much power is needed for the 2 TB unit you are considering. If you under-power it, OR if you get it to work on USB3 but later plug it into USB2, I don't think it will damage the data on the unit. It simply will not work and you won't be able to access the drive.

My last paragraph about the backup system confused you, so let me clarify. The external drive has a capacity of 500 GB. I have two internal HDD's a little smaller, but they total over 500 GB. However, they are nowhere near full. Now, the issue I worked around is that, once I make a clone copy of an internal HDD on the external unit, my mobo has no way to BOOT from that external unit. The mobo BIOS, of course, contains code to boot from a HDD on an internal SATA port, but no code to boot from a drive on either an eSATA port or a USB2 port. So what most people would do if their internal HDD craps out in that case would be to use another computer to clone from the copy on my external HDD to a new HDD. Then you could swap that new HDD into my machine as an internal and boot up.

I avoided having to use the second machine. As a side issue, when I made the clone copies from my two internal HDD's to my one external unit, it was done as two cloning operations. In each case I told the cloning software to make the clone copy on the external a bit smaller so they would both fit, but large enough that they contained all the original HDD had. When you make a clone copy, it goes into a Partition on a HDD - it does NOT have to occupy the entire destination unit. So the clone copy of my internal C: drive was made first as a bootable Partition on the external unit. Then the clone of the second internal HDD was made as a non-bootable (data only) copy to a second Partition in the remaining space. Now the external unit looks exactly like a single internal HDD that contains two Partitions - a bootable one and a non-bootable data volume.

To prove the plan works, I then went into my desktop machine and disconnected both HDD's. Then I opened up the external enclosure, removed the HDD from it, and mounted that HDD in my desktop machine, connecting its data cable to the SATA port from my "regular" C: drive. So now that 500 GB unit is a bootable internal HDD with two Partitions on it containing complete copies of all the stuff from both my "regular" internal units. I simply closed up the case and switched on. The machine booted completely normally as it should. The only difference was, those two "drives" (actually, Partitions on one HDD unit) were a little smaller than the originals. Since the test worked, I just reversed the process to get back to the starting conditions.

Now, in the case of a real failure of my internal C: drive, I would do just that up to successfully booting back up. THEN I would buy a new HDD and install it in my machine, then clone a copy of the first (bootable) Partition from the 500 GB unit to the new HDD, making that clone of a clone take up ALL of the space on the new replacement HDD. Then I'd remove the 500 GB unit and reconnect things so the new unit was on the SATA port that always had been used for the boot drive. I would have done the replacement job without needing a spare computer, and as a side benefit I'd have had my machine working again within 15 minuted of a failure of the original C: drive.
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May 26, 2014 10:22:39 PM

Sounds like a great feature if the c drive is failing, i might benefit from a smaller homemade one, which is more acceptable in price
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