Possibility of hdparm on Mac OS X

[Bradley Giesbrecht]

There are other people who claim to improve performance using dd to  
write zeros to disk.

I don't have any ssd drives to test on but if you send me one I will :)

// Brad

On Aug 27, 2010, at 8:21 AM, Scott Haneda wrote:

> On Aug 27, 2010, at 12:31 AM, Ned Deily wrote:
>
>> In article <6EB398EB-F4ED-4A75-A5CC-F4A3447584EF at newgeo.com>,
>> Scott Haneda <talklists at newgeo.com>
>> wrote:
>>> The one command I am after is ATA Secure Erase, the rest would be  
>>> nice, but
>>> that is the main one.
>>
>> Doesn't Apple's /usr/sbin/diskutil provide this already, i.e. its
>> secureErase function?  (see "man 8 diskutil")
>
> Unfortunately no.  The command I am after, ATA Secure Erase is not  
> quite the same as the one built into Mac OS X.  It is, I believe,  
> only useful and targeted to SSD drives.  SSD drives will start with  
> a certain measure of performance that falls off by about 15% over  
> use in the next week to month.  It then flatlines around that point  
> for some time.
>
> If you want your drive to work as fast as it was when it was new,  
> you need to run this command against it.  This will write out the  
> drive in a certain way that SSD drives are able to perform like  
> new.  A Mac OS X Secure Erase, I believe, would only erase the  
> drive, and add additional wear to it, actually making you worse off  
> than you were before, albeit in a very minor way.
>
> https://ata.wiki.kernel.org/index.php/ATA_Secure_Erase
> -- 
> Scott (* For off-list contact, replace talklists@ with scott@ *)
>
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