SSD Optimisation for MacOS

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[MacUser2525]

Is it accurate that the timestamp is changed every time a file is read?

Is this timestamp a part of the file thats read, or is it simply a part of a lookup table elsewhere - which would itself presumably be being constantly updated.

Yes it is the last access time and not really sure where it is stored on OS X but in Linux/Windows it is part of the stored metadata of the file allocation table or FAT as you often read it shortened as, brief explanation below from a quick Google search on it.

http://www.unix.com/tips-tutorials/20526-mtime-ctime-atime.html

 

[Consultant]

Spotlight can use last opened attribute to put files / folder on top of searches.

You don't really need to optimize SSD (if you get a drive that takes care of trim). It's just some tech voodoo. You don't have to worry about it too much.

 

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[MacUser2525]

Thanks for this - having read it and some of the other links from the page, it seems only logical that the last read or atime parameter is recorded centrally and not within the file itself.

Otherwise searching for files that have been accessed say within the last hour, would require that all files on the disk be read sequentially to check! Same with the spotlight sort mentioned below.


Yep am coming round to the thought that it's probably better just to use the disk normally and accept that it won't last forever - just like mechanical hdds.

Picked up an OCZ vertex 2 (after my crucial m225 had failed) after i'd read it was a good boot drive for the Mac. Think it has some form of GC and will just avoid filling it, to allow the GC to work.

Thanks again to both of you.

Your welcome if you go to Anandtech link below there are a few words in there about OS X and its lack of trim, reading the article and the comments about it I came to the conclusion as the other poster has don't worry about it the drive should last awhile without it. Personnaly what I have done is every once and a while clone my SSD to an external drive boot off that then format the SSD and clone back, mine lacks any sort of garbage collection.

http://www.anandtech.com/show/4010/kingston-ssdnow-v-plus-100-review

 

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[karsten]

interesting read. this bit makes me wonder just how soon apple will support trim.
'The new firmware enables two things: very aggressive OS-independent garbage collection and higher overall performance. The former is very important as this is the same controller used in Apple's new MacBook Air. In fact, the performance of the Kingston V+100 drive mimics that of Apple's new SSDs'
if the aggressive gc mentioned can keep the majority of drives running at full speed for the warranty period of applecare, then maybe apple will decide this is a more cost effective way of dealing with ssd performance and not bother developing trim.

i agree. i think they will skirt the trim issue by using gc instead. it gives them a way to distance themselves from seeming to follow ms as a trendsetting company too