Possibly rather important
"The advantage of the TRIM command is that it enables the SSD's GC to skip the invalid data rather than moving it, thus saving time not rewriting the invalid data. This results in a reduction of the number of erase cycles on the flash memory and enables higher performance during writes. The SSD doesn't need to immediately delete or garbage collect these locations, it just marks them as no longer valid." [1]
As no one seems to have any answers, I've decided to look into this issue further myself. With the feeling that TRIM is important, if
perhaps not vital.
Per TRIM, some say it can be dispensed with, others that it cannot. Turns out that any SSD should work perfectly fine initially without TRIM. However in time as they fill up and need to remove old data towards storing new—then the problems arise. TRIM allows a SSD to more efficiently do its garbage collection function (or sorting of existing data towards storing new, even as this can be done in the moment or prior to). Either way, a SSD with TRIM will operate faster and last longer.
The flash memory of a SSD has a limited number of times it can be used. Ideally use would be apportioned evenly, instead of overuse in certain sectors, using them up prematurely. TRIM would seem to help this in part. It seems TRIM is in effect communication between the computer and SSD, allowing the latter to perform its garbage collection most efficiently.
An exception to this appears to be SSD's using a different protocol. SandForce SSD's would be an example, such as the Corsair Force, with what is termed DuraWrite. The architecture of such a SSD is different from others, with TRIM in circumstances not available—but more importantly not necessary. If and when enabled, TRIM would allow this SSD to be all the faster, theoretically, but in practice one then runs up against system limitations, such as SATA 3. As explained:
"In an SSD with DuraWrite technology (row 2 left), less data is physically written to the drive in the first place, so there is more free space available for GC. In fact, the amount of space available in a non-TRIM environment is comparable to the space available in a TRIM environment on a conventional SSD." [1]
In further explanation:
"SandForce gives the name "DuraClass" to the overall technology incorporated in its controllers. SandForce controllers do not use DRAM for caching, which reduces cost and complexity compared to most other SSD controllers. SandForce controllers also use a proprietary compression system to minimize the amount of data actually written to non-volatile memory (the "write amplification") which increases speed and lifetime for most data (known as "DuraWrite")." [2]
Two of the more popular SSD options are the Crucial M4 and Samsung 800 series, as in 830, 840, or 840 Pro. For TRIM the Crucial may be the better choice, as apparently allowing it through such third party software as Trim Enabler. It seems Samsung
may be compatible with this software as well. There are issues, however. Aside from TRIM, it seems that firmware updates are possible with the Crucial in a strictly OSX environment, whereas apparently not with Samsung without reverting to Windows. Their "Magician" software is currently not OSX compatible; so unfortunately no firmware updates or TRIM enabling via that with just a Mac.
Apple in its wisdom, and possible desire to sell its own massively over priced SSD's, does not support TRIM on any SSD not its own. Third party solutions, such as Trim Enabler, must be used instead. Although apparently those able and willing to use terminal commands can activate TRIM as well. Either way, it appears that TRIM rather than via Apple is lost on every OSX update, and must be reenabled. So in just that, a pain. Additionally, there have been various serious issues reported in using Trim Enabler. Supposedly this has since been corrected, but as TRIM must be reenabled at times, an ongoing possible risk in this seems a possibility.
No SSD will last forever, they have only so many cycles. Although in practice this limit is apparently so high that the advance of technology, and desire to at last catch up with it, will insure the effective life of a SSD will be met before its technological lifespan will. But the use of TRIM or not could shorten the assumed lifespan, and the health and speed of the SSD increasingly until then.
In summation,
my speculation that—all else being equal—the Samsung 840 Pro may currently be the most capable SSD and best option for use in a Macintosh. But that in consideration of TRIM and firmware updates it may prove a secondary choice to Crucial. And that until such matters as TRIM are resolved that real life practice would see better long term performance, and less headaches, with a SandForce type SSD.
Although, even if guaranteed, the performance and life degradation suffered without TRIM (and possibly, lack of firmware updates) may not be severe enough to be more than academic for what may be but their several year lifespan in use. Or not, and then you've got a problem.
