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Question about TRIM support for 2 SSDs in OSX

Last response: in Storage
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January 7, 2013 3:19:15 PM

Hey guys, I have a complicated—seemingly—question for you all. So, here goes:

I've been reading how important it is to have TRIM enabled on an SSD.
I'm in OSX, on a Mac Pro (early 2009). I have a very small SSD—60 GB—as my boot disk for which TRIM has been enabled. (I can confirm this) I also, however, have a larger—512, 6 gb/s—SSD running through a Raid controller, internally. In addition to a hardware raid I have setup for two standard HDDs, this Raid controller allows my 6 gb/s SSD to read at full speed, rather than 3 gb/s, which is all my Mobo supports. (A difference of about 250 mb/s read time for me!) The reason the large SSD is not my boot disk is because my RAID controller is not bootable in OSX, hence the need for the smaller boot disk. Not an important issue. (It may be important to note here that I NEED that 6 gb/s connection speed to run some VERY intensive music samples for film scoring, so the RAID card is a necessity at this point)

Anyhow, my question is this. Since my 512 SSD is running through a Raid controller, I cannot see it in my system profiler, nor does TRIM enabler (a program that enables TRIM in OSX) see it when I run that program. Seemingly, I cannot enable TRIM on this larger SSD, and if it is enabled, I cannot confirm that it actually is active.

SO ... I understand that lots of read/write activity on an SSD, without TRIM enabled, causes a drive to deteriorate much faster as the management of free space on an SSD is tricky. Therefore, would I contribute to my 512 SSD's degradation if I wrote a script that erased all free space on the drive (essentially what TRIM does, but not as elegant) on a regular basis, or would this tax the drive unnecessarily causing it to fail faster?

Thanks for any answers you may have!

-K
a b G Storage
January 8, 2013 11:01:35 AM

Your script would only be able to access the SSD logically, not electronically and probably decay it 100x times faster.
- It would confuse the cr&p out of the wear-leveling in the drives firmware for example.
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January 13, 2013 10:46:35 PM

I too am on a similar hunt. So far, I've only found softraid to be an option. Seems the only real way to get trim in OSX, especially in MacBooks.

Some raid controllers, may have good garbage collection, but I'm not sure about them, and in my case, I'm searching for solutions for my notebook.

Good luck on your hunt, let us know if you find anything.
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a c 523 G Storage
January 13, 2013 11:02:05 PM

Modern SSDs do not rely solely on TRIM to maintain drive performance; they also use idle Garbage Collection.

Just Log Out (not Shut down) overnight before you go to sleep once every other week or so to allow GC to do its thing.
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