
Apple adds SSD TRIM support to Mac OS X 10.7 Lion beta - msmith
http://www.appleinsider.com/articles/11/02/25/apple_adds_ssd_trim_support_to_mac_os_x_10_7_lion_beta.html
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InclinedPlane
It's disappointing that this has been lacking, it's a very important feature
for proper use of modern SSDs and it's been in Windows since late 2009 and
Linux since early 2010.

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masklinn
Which so far as proven not to be so important, especially as Apple has
historically been using SSDs very resilient to that issue (according to
Anandtech's tests of the 2010 MBAs).

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r0s
If you think an SSD can be "resilient to that issue" you don't understand the
problem. From the Anandtech article you mention:

"Either the Toshiba controller is using over 12% of the total NAND capacity as
spare area, or there's only 30GB of usable flash on the drive."

So they're lying about capacity to offset the need for TRIM. Who knows the
long-term implications of that decision? I noticed the benchmark didn't
saturate the drive to capacity before speed tests. Maybe they didn't mention
it, sloppy either way.

Perhaps long term results aren't relevant; a frequent upgrade cycle is
assumed. I suppose the average user is agnostic to the capabilities of their
hardware, like you suggest.

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Retric
There is no reason trim needs to be done in the OS. (Not that I know of any
drive that does this, but it should be possible without any OS interaction.)

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wmf
Without TRIM, there's no way for an SSD to know (without cheating) which
blocks are considered free by the filesystem. Increasing the FTL free space
allows an SSD to absorb more writes at full speed before needing to GC.

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Retric
A SSD that understands NTFS and the other major file systems while "cheating"
is not impossible. Also _The TRIM command does not work on RAID volumes_ so
there is plenty of room for improvement.

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ComputerGuru
It's unfortunately NOT supported for everyone.

[http://neosmart.net/blog/2011/os-x-10-7-lion-adds-trim-
suppo...](http://neosmart.net/blog/2011/os-x-10-7-lion-adds-trim-support-but-
not-for-all/)

That's on a top-of-the-line C300 256GB. It's detected as an SSD, but no TRIM
support though the drive itself does have TRIM.

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blinkingled
Hmm, typical Apple - we will support only what we ship. But it should be easy
to enable for 3rd party drives - probably there is a plist somewhere that
maintains a list of supported drives that can be hacked or worst case a kext
needs to be hacked.

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sjs
Yes typical Apple, they view their products as appliances. As Steve Jobs said
in 2006 or 2007[1]: "We're getting to the point where everything is a computer
in a different form factor. So... So what? Right, so what if it's built with a
computer inside it. It doesn't matter. It's "what is it?" How do you use it?
You know, how does the consumer approach it? And so who cares what's inside it
anymore."

Of course we still see them as computers because we're geeks, but for most
people they simply are appliances. If things break they're not going to open
up the machine and take a look, just like their TV, washing machine, etc.

Whether or not you feel that computers _should_ be appliances, Apple has
_always_ had this view of their products for better and for worse.

[1] <http://www.youtube.com/watch?v=Vc8QXzYQoBY>

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blinkingled
The Mac Pro is an appliance? Apple sells Graphics Cards, RAID Cards and stuff
as add-ons to the Mac Pro. Mac Pros also can use SSDs and not many are going
to be bought from Apple or packaged inside when it is bought.

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sjs
Good point. The Mac Pro is definitely a computer, but it is the exception. The
iMac, MacBook + Pro + Air, and Mini are not like that.

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CognitiveLens
danudey left a helpful link to a comment I made recently about TRIM support in
Lion. Apparently, 10.6 is doing some good SSD maintenance even without TRIM
support, and SSDs do not experience the same performance drops as they would
on a Windows machine without TRIM support, but it is not clear why this is the
case.

[http://www.bit-tech.net/hardware/apple/2010/07/01/mac-ssd-
pe...](http://www.bit-tech.net/hardware/apple/2010/07/01/mac-ssd-performance-
trim-in-osx/7)

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r00fus
Does that apply to all SSDs? From what I gather TRIM is just a spec for
formalized OS-level garbage collection hooks. Some disks (like Apple-installed
Samsungs) do GC at the disk-level.

My Sandforce (Vertex 2) has disk-level GC (as well as TRIM), and sometimes
will block for a long period on writes now on OSX... I haven't tried it on a
different OS yet.

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wmf
As I said in the other thread, displaying the fact that an SSD supports TRIM
does not prove that HFS+ uses TRIM, but it's a good sign.

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ben1040
To someone who bought a 2010 MBA in October and doesn't get an OS that
supports TRIM until this summer, what's going to be the impact on the useful
life of the SSD?

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hackermom
None, I'd say. I've been running an older X25-m generation on a Win2K box for
14 months now. No TRIM in firmware, no TRIM in W2K. Disk has been filled and
cleaned out numerous times since I bought it and it still performs adequately.
I'd be surprised if your SSD would suffer from the few months until you get
TRIM in 10.7.

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PStamatiou
On the other side of things, I've owned 3 X25-M's. A first gen that died in 9
months, a second gen (RMA replacement) that just started acting weird and
corrupting things last month (was about 15 months old and was in a RAID 0
array with another X25M but I undid the array and began using the better of
the two X25M's). Needless to say I use Dropbox, Time Machine and Carbon Copy
Cloner very often.

related: <http://paulstamatiou.com/ssd-raid-performance-9-months-later>
<http://paulstamatiou.com/ssd-corrupt-failure-intel-x25m>

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issaco
interesting discussion of TRIM here:
[http://www.realworldtech.com/forums/index.cfm?action=detail&...](http://www.realworldtech.com/forums/index.cfm?action=detail&id=116082&threadid=115697&roomid=2)

(read the thread segments which relate to TRIM)

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wooptoo
Bend over and get screwed by Apple. At every OS update.

