SSDs with "onboard" TRIM

There exists no such thing as onboard Trim.
Every SSD has garbage collection. GC only works maximally efficiently if Trim is enabled and it has knowledge about valid and non valid data. Without Trim you eventually have an essentially 100% full SSD. That can still work okay (if there is enough spare area) but GC has to work much harder, which leads to higher write amplification, which means NAND endurance is much more stressed.

There is no such thing as onboard Trim. There never was. Most SSDs released lately have a rather small spare area for more efficient space use, which isn't a problem with Trim enabled but it really should be enabled. Old Sandforce SSD had 27% spare today they are at 7% or less and non sanforce are usually very low with sometimes virtually no spare at all.
If you don't use Trim leave some space (10% at least) unpartitioned.

Trimenabler just does for any SSD what Apple only does for its own SSDs. You won't get an Apple SSD afaik so just use Trim Enabler.

 

You can think of it as follows: Apple's SSD driver does not use TRIM command on any other SSD than their own. What TRIM enabler does, is just override the drive identification code in said driver, so it will validate all drives as Apple's.
In more detail, there is a string
APPLE SSD
in the driver code that simply gets overwritten with zeroes.
All Apple SSDs have this APPLE SSD as part of their name in identification string:

Apparently the hack simply makes any drive name match so TRIM gets used on the drive.

 

Its amazing how Apple won't implement TRIM into Mac OS except for its own SSD drives.

 

It helped me to think of it this way:

TRIM is a Operating System command that is issued to the device telling it a file/folder/etc has been deleted.

Garbage Collection is a Firmware Level feature that actually does the 'deletion' of the file/folder/etc on the SSD. (it's not really a deletion, but for simplicity's sake, we'll call it that)

For most efficient (speed/longevity) use, TRIM + GC is required.

Yes, OWC...even you need TRIM.

I would highly recommend the Samsung 840 EVO line. They have a 2.5" SSD and a mSATA SSD (up to 1TB) for guys like me with a mSATA slot.

Thank you, Alienware. I can carry around a 2x1TB SSD RAID0 in my laptop. Sweet.

 

Basically GC is the same thing defragmenting was for HDDs. It consolidates empty space for better write performance, because SSDs never overwrite the old data but just write updates elsewhere and delete the old stuff whenever they have time to. GC has no clue about what a file/a folder or anything is or whether it is deleted. It knows LBAs and when one is overwritten (new data) it knows it can delete the old data.

I think they had just some bugs with early firmware versions relating to Trim on some SSDs. Because they didn't want to deal with the support questions they just disabled Trim. They simply never revisited that decision. Windows/Linux enable Trim everywhere and expect the SSD manufacturers to fix the firmware. I assume there also was some bug in Apple's Trim implementation and they didn't figure it out so they just went the save route.
Today it is kind of a bad joke. As we know Apple they always like it when there own stuff behaves better. Safari can do flash on the iGPU, Chrome cannot. VLC took forever to work on the iGPU. This SSD Trim business is just another example, where Apple doesn't seem particularly interested in having 3rd party stuff be too appealing.

 

I doubt Apple will revisit TRIM for 3rd party drives. Most recent Apple machines don't have (officially) user-serviceable drives anyway so the point is probably moot.