Pros and Cons of zeroing a new hard drive.

Hi, again!

I would guess 5 hrs to zero? That is why I break it down into partitions instead.

Erase tests the first and last 1000 sectors, areas that have to be error free and are outside of the user environment afterwards. And takes a minute.

Why zero? because almost any drive today can ship with weak or bad sectors.

If you can, I'd start it at 6 PM and let it go overnight or something.

But even with Apple Disk Utility, zeroing a drive is not as effective or reliable as zeroing the same drive with WD's Windows Diagnostic program. Not sure why, just been confirmed a number of times by different, seasoned users.

I'd buy Intech benchmark utility $29 and use ZoneBench to pound on the drive partitions heavily for hours, and take your time, and then put the drive to regular use. That is probably the best insurance for avoiding pitfalls and disasters and learning the hardway with less risk. And of course, backup, and backup of backup.

I have seen even a "good drive" show improved I/O after extended testing and zeroing in benchmark and I/O graph pattern.

WD Green Power 1TB
HD Tune: WDC WD10EADS-00L5B1 Information
Firmware version : 01.0

WDC WD10EADS-00L5B1

Transfer Rate Minimum : 41.6 MB/sec
Transfer Rate Maximum : 95.6 MB/sec
Transfer Rate Average : 74.3 MB/sec
Access Time : 14.0 ms
Burst Rate : 115.7 MB/sec
------

Take a look at the before and after for Black Caviar 640:

WD Black Caviar 640GB


HD Tune: WDC WD6401AALS-00L3B2 Benchmark

Transfer Rate *Minimum : 30.2 MB/sec*
Transfer Rate Maximum : 118.1 MB/sec
Transfer Rate *Average : 88.4 MB/sec*
Access Time : 12.1 ms
*Burst Rate : 107.2 MB/sec*
---------
HD Tune: WDC WD6401AALS-00L3B2 Benchmark

Transfer Rate *Minimum : 59.1 MB/sec*
Transfer Rate Maximum : 118.1 MB/sec
Transfer Rate *Average : 95.5 MB/sec*
Access Time : 11.9 ms
*Burst Rate : 125.7 MB/sec*
------
What you don't see is the graph went from +/- of 5MB/sec "jagged line" to flat.

I probably need a fliker account to host images to best show graph.

Hitting the gas, then the brakes, is hard. Or driving at 90 mph.

Think of it as 'breaking in' and first 4000 miles before first oil change.

As I said before, it helps, a new drive is stiff, and some use to have a built in throttle or govenator to keep it under 60 mph.

You want to write to the whole drive and test every sector. I use to load large 4-8-20GB files until I filled the drive to 92%.

Also, writing zero is not really a good test, whereas writing a mix of zero and ones, 9s, "X'FF'" does a better job.

Living in the city, the car would have a build up deposit. Taking it out for a spin on the open road would give it a chance to clean out, open up, and get some fresh air and fuel through the system.

Take your horse out for a run. If you don't, it gets stiff I suppose. Or a swimmer gets out of shape.

Intech is Mac program.

http;//www.intechusa.com and sold by OWC.

You may not know it has bad sector, or it gets patched.

If you run Disk Warrior it has diagnostic and writes the SMART log of used and spare blocks, which is how you could tell.

Not everyone checks the ice before going out skating and trusts others haven't broken through so it must be safe!

TechTool Deluxe. I would upgrade it to TechTool Pro 5.03.

Use DU to partition into 4.
Then do secure erase 7-way write on one partition.
Zero another partition.
And when done click on DW's Diagnostic -> Manual AND have the Console open and System Log showing - you will see DW write a couple lines out to that.

You may never know or it could be caused by random sporatic events, crash, or corrupt preference, or nothing at all.

Even memory can have soft errors. And some errors are correctable or recoverable. Your disk drive also has its own cache and ECC memory.

No. DW is used to repair a damaged directory. Disk Utility is used to partition and format the hard drive. For a new or unknown hard drive do this:

Extended Hard Drive Preparation

1. Open Disk Utility in your Utilities folder. If you need to reformat your startup volume, then you must boot from your OS X Installer Disc. After the installer loads select your language and click on the Continue button. When the menu bar appears select Disk Utility from the Installer menu (Utilities menu for Tiger or Leopard.)

2. After DU loads select your hard drive (this is the entry with the mfgr.'s ID and size) from the left side list. Note the SMART status of the drive in DU's status area. If it does not say "Verified" then the drive is failing or has failed and will need replacing. SMART info will not be reported on external drives. Otherwise, click on the Partition tab in the DU main window.

3. Set the number of partitions from the drop down menu (use 1 partition unless you wish to make more.) Set the format type to Mac OS Extended (Journaled.) Click on the Options button, set the partition scheme to GUID then click on the OK button. Click on the Partition button and wait until the process has completed.

4. Select the volume you just created (this is the sub-entry under the drive entry) from the left side list. Click on the Erase tab in the DU main window.

5. Set the format type to Mac OS Extended (Journaled.) Click on the Options button, check the button for Zero Data and click on OK to return to the Erase window.

6. Click on the Erase button. The format process can take up to several hours depending upon the drive size.

The process is completely automatic. When completed the drive is ready for use. You would not need to zero a drive that was already properly partitioned and formatted for OS X unless the drive becomes unrepairable using Disk Utility or Disk Warrior.

Most likely you won't. Bad sectors arise out of use - grown defects. Drives generally won't come from the factory new with bad sectors because the drives are already formatted - usually for PCs. Doing the preparation I outlined is necessary mainly because the drive will not otherwise work in a Mac.

Spare sectors are there for a reason. If it can't map it out and reassign to a good sector, yes.

TechTool Pro has a good media scan - but, it doesn't / did't attempt to fix or map out (seems odd). Try zero and retest (takes too long). And if that doesn't work and media scan shows error, then use 7-way write erase.

Disk Warrior doesn't zero a drive, but it does report the number of spares left, used, etc.

Any program that purports to do SMART test and analysis, unless it is from the vendor, isn't worth the bits it is written on really. TechTool Pro and Intech Speedtools do have half way decent SMART reporting and test. Disk Warrior just has basic - most people forget it has Diagnostic tab.

I don't like to deal with RMAs. You get back a recertified drive. At least it is certified, which is what WD's Windows tool might do.

It takes too long usually and people don't want to be bothered, or what to do, and often trust a program that may or may not fix the problem. SoftRAID is great because it alerts you if it has trouble reading or writing to a disk, so you know immediately you want to take steps. And some feel, just for that it is worth the $149.

I have seen two that clearly had trouble, one had multiple bad sectors in two areas, 750GB drive. WD Caviar Blue from last April. They did not just show up later.

Other drives have shown that while they may or may not have had errors, they were not performing up to par.

Drives do ship with errors.