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The ARP Hard Disk Guide

This guide was written in response to the numerous fallacies about the hard disk that are still being propagated in many forum discussions. Although

many articles have covered these topics, it is apparent that hard disk urban legends are still more popular than the simple truth.

So, let’s get down to basics and examine some of these common fallacies or myths and debunk them!

Myth #1 :
Formatting a hard disk too many times will cause it to fail.

Truth :
To put it shortly, formatting your hard disk will NOT reduce its lifespan. Yes, formatting is popularly thought to reduce hard disk lifespan but that isnothing more than a myth.

Formatting is NOT a stressful event for the hard disk. The read/write heads do NOT touch the platter surface, so damage to the platter only occurs if

there is any shock to the drive during operation. You can format your hard disk 20 times a day, every day and it will not be more likely to fail than any otherdrive.

Myth #2 :
Formatting a hard disk causes a layer of *whatever* to be deposited on the platter surface, causing bad sectors to form.

Truth :
Formatting will not deposit any layer of “anything” on the platter. The hard disk is a sealed environment so there is very little dust inside the hard disk.

Even if there is dust, why would formatting deposit anything on the platter?

Myth #3 :
Formatting the hard disk will stress the needle (head actuator).

Truth :
Formatting is done contiguously. This means formatting is done in a serial order, i.e. sector 500, sector 501, sector 502, etc. There is very littlemovement of the head actuators.

Therefore, formatting will not stress the head actuators.

Myth #4 :
Defragmenting the hard disk will stress the needle (head actuator).

Truth :
That is actually contrary to the truth. Defragmenting the hard disk may involve a lot of seeking as the hard disk rearranges its data in a contiguousfashion. This allows the read/write heads to read large amounts of data without seeking all over the platters.

However, after defragmentation, the hard disk no longer needs to seek all over the platters for your data. This reduces the amount of head actuator

movements as well as greatly increase the hard disk’s read/write performance.

Therefore, while it may be technically correct to say that defragmenting your hard disk will stress the head actuators, the truth is defragmenting your harddisk will reduce the amount of seeking from then on and thus reduce the head actuators’ workload.

Myth #5 :
If your hard disk has bad sectors, formatting will cause more bad sectors to appear!

Truth :
If your hard disk has bad sectors from recurrent head crashes, then the number of bad sectors is GUARANTEED to increase as time goes by.

The reason for the increased number of bad sectors when you format the hard disk is because formatting your hard disk reveals the new bad sectors!

Don’t forget, when you format the hard disk, the format utility will check for and reveal the new bad sectors.

So, formatting will not increase the number of bad sectors in a failing hard disk. It just reveals what’s going on.

Myth #6 :
Downloading too much *stuff* from the Internet will reduce your hard disk’s lifespan.

Truth :
Downloading “stuff” into your hard disk all the time will not reduce your hard disk’s lifespan.

Remember, your hard disk is continuously spinning even when it is not reading or writing. As long as it is spinning, it is just as likely to die when it isidling as it is when it is reading or writing data.

Myth #7 :
Insufficient power causes bad sectors in hard disks.

Truth :
Insufficient power or power cuts won’t create bad sectors in your hard disk. Whenever there is not enough power or a power cut, the head actuators

automatically park the heads so that there is no risk of head crashes on the platters.

So, there is no way insufficient power can cause bad sectors.

Myth #8 :
Cheap power supplies will “slowly kill” your hard disk.

Truth :
Cheap power supplies will NOT “slowly kill” hard disks. If a cheap power supply fries and sends a power surge to your hard disk, it kills the hard disk instantly.

If it cannot provide enough power, your hard disk won’t run properly or just plain won’t run at all.

Myth #9 :
If your hard disk keeps spinning up and down, that is because the power supply sometimes has enough power to spin up the hard disk and

sometimes, it cannot provide enough power and the hard disk spins down again.

Truth :
If there is a loss of power or insufficient power to the hard disk, it will power down and cause the computer to hang. Even if power is restored, the hard disk won’t resume operation like nothing happened. You will need to reboot the computer.

The spin-up, spin-down activity is actually a symptom of the hard disk’s recalibration process.

Myth #10 :
Head parking is the cause of loud clicks from your hard disk.

Truth :
That can either be a symptom of the hard disk’s thermal recalibration process or it can be due to head crashes on the platters.

Myth #11 :
The head actuators are powered by a motor that can fail due to excessive use.

Truth :
Current head actuators are actually not powered by any motor.

Yes, in the past, head actuators were powered by a stepper motor. But current head actuators use the voice coil mechanism which uses electromagnetic force to move the heads.

So, if the head actuators are not powered by any mechanical motor, how can “its motor” fail?

Myth #12 :
Frequent parking of the read/write heads will make the head actuators’ motor fail earlier.

Truth :
See Myth #11 regarding the head actuator’s “motor”.

In addition, please note that head parking in current hard disks occurs automatically whenever power is cut or when the hard disk powers down. It is not an active process.

The head actuators actually have springs to keep them in place. When there is power, the actuators are moved against the spring tension. When power is cut, the actuators automatically retract.

Therefore, even if head actuators were powered by a motor, head parking will never cause that motor to fail.

Myth #13 :

The hard disk only spins up when it needs to read or write data. It spins down when it is idle.
Truth : Actually, the platters are kept spinning all the time, unless you have set it to spin down to save power after some idle time.

Myth #14 :

It is better to spin down the hard disk whenever you can to reduce stress on the spindle motor.
Truth : Normally, the platters are spun up at start up and kept spinning after that. The spinning up process is the most taxing part on the hard disk’s spindle motor. Maintaining the spindle speed requires a lot less effort.

If the platters have spun down and you need to read/write something on the platters, you will need to spin up the platters to full speed before you can read or write.

Therefore, it is better to keep the hard disk spinning for better performance and to reduce stress on the spindle motor.

Myth #15 :

Sudden power cuts can cause bad sectors!
Truth : Bad sectors are not caused by shutting off your computer suddenly.

It used to be in the case in the old, OLD days when you had to park the hard disk heads before you turned off your computer. These days, the voice coil actuators will automatically park the read/write heads whenever power to the hard disk is cut off.

Therefore, there is no risk of any head crashes that can create bad sectors.

Myth #16 :
Some bad sectors are “virtual” bad sectors that can be repaired by formatting the hard disk.

Truth :
There are also no such things as virtual bad sectors and physical bad sectors.

A bad sector is a sector that cannot be written to or read from properly. It can be due to an eroded media or direct physical damage to the media. It cannot be repaired by any software and formatting will not restore it.

Myth #17 :
There is nothing to worry about bad sectors because you can “erase” them by formatting the hard disk.

Truth :
True, low level formatting can replace bad sectors with good sectors on the spare tracks that are part of every hard disk.

However, performance suffers because the heads have to seek to the spare tracks. In addition, there are only a limited number of spare sectors available on any hard disk.

Finally, bad sectors are a sign that something is wrong with the hard disk. Even if it was due to a single head crash, that traumatic event would have created debris within the platter compartment and a damaged head. The debris can gradually cause scratches and erosions on other parts of the platter while a damaged head will not be aerodynamically stable and will be more likely to crash in the future.

In other words, if you have critical data, it would be a smart thing to back up your data and replace the hard disk when you start detecting bad sectors.The hard disk may go on for a long time without more bad sectors appearing but the risk of it dying is real and should not be ignored.

Myth #18 :
You must format your hard disk every to improve performance.

Truth : This is yet another common fallacy. Formatting your hard disk regularly will NOT improve your hard disk’s performance.

If you notice a significant degradation in your hard disk’s performance after several months, this is because the data in the hard disk has become so fragmented that the read/write heads have to seek all over the hard disk while reading or writing data.

Try defragmenting your hard disk, instead of simply formatting it.

Myth #19 :
The hard disk can only be installed in the horizontal position.
Truth : Hard disks can be installed in any position - horizontal, vertical, even upside down!

Myth #20 :
If you want to use a hard disk in the vertical position, you must first reformat it in the vertical position!
Truth : Hard disks will work in any position. You do NOT need to reformat it before using it in vertical position or even upside down!


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  1. 1 ความคิดเห็น: Responses to “ Hard Disk Myths Debunked ”

  2. By d70user on July 18, 2007 at 12:42 AM