Q: Samsung 850 EVO and TRIM?

Hi, you can enable trim after you backed up your important things. i enabled it and havent got any problem and see the performance of SSD better but some of my friends faced with grey screen on start up.

Also i can say you wont have problem as long as Apple let you to do something on your Mac

I also have a Samsung 850 SSD, but mine is the 500 GB size.

I enabled Trim about a month ago, and it has been working good.

To enable TRIM, first save all your open documents as this will reboot your Mac.

1) launch Terminal.

2) Type "sudo trimforce enable".

3) Confirm that you want to enable trim.

4) Reboot your Mac.

To verify that TRIM is enabled, click the Apple icon in the top left of your screen. Choose "About this Mac" -> "System Report" -> "SATA/SATA Express" and look for the entry "Trim Support". It should say "yes" if trim has been enabled.

Kim

Thanks, just enabled TRIM. like ur instructions.

I replaced my HDD with Samsung 850 500GB a few weeks ago on my MBP early 2011 13"...

If It Ain't Broke.........Just my two cents.

I installed Samsung EVO 850.   Trim is not enabled and my SSD flies like a jet.  So, I am not seeing any need to enable Trim, since it all runs great already.  

Best regards

Dropped by Samsung website to check on the EVO 850. yup, Samsung say this SSD support TRIM.

see link below.

http://www.samsung.com/semiconductor/minisite/ssd/product/consumer/850evo.html

Don,

You don't understand what Trim is.  Trim is basically a "defrag" for SSD drives.  You may have been flying in March, but if you still don't have Trim enabled today, your drive is probably going slower than it was.  Trim keeps your drive nice and tidy so it can fly for the long term. 

I had previously googled extensively regarding TRIM on Samsung SSDs.

I installed my Samsung 850 EVO 250GB SSD on my Macbook Pro 13" mid 2010 and decided not to enable TRIM.

fast forward 9 months later, i feel my applications might be slightly slowered and my application "clean my Mac 3" tells me that i need to repair my startup disk.

today, i repaired it and enable TRIM, hopefully this works for me as well as for people who has the same questions.

I believe it will be faster and so far my laptop feels great, if not greater and ever so slightly faster.

When you delete a file from a HD, the space it occupied can be written to immediately. When you delete a file from an SSD, the space needs to be erased first by the SSD controller.

Two gotchas. First, the minimum contiguous space that can be erased is often larger than what the file occupied so before erasure, all the still good stuff in that space has to be moved somewhere else first.  Second, the HD and the OS both know about file deletion making the space free, but the SSD controller doesn’t, so when the good stuff is moved prior to erasure, the deleted stuff goes too.

TRIM is the function built into the OS that tells the SSD the deleted file’s space is erasable but it’s only on by default with Apple SSDs. That’s what enabling TRIM is for with non-Apple SSDs.

A key idea is that the space is flagged as available when the deletion takes place which means TRIM must be running continuously to get full benefit and any such benefit is lost for deletions prior to TRIM being enabled. So there will be no sudden magical fix for a drive slowing down because the SSD controller’s Garbage Collection has previously had to deal with “secretly” deleted files which are still taking up space.

Thanks fatmac!

I guess that means i need to reformat my SSD and get a clean install of OS and enable TRIM immediately to fully enjoy the benefits?

Considering that your SSD has been in use for quite a while and the contents would need to be reconstructed from scratch (unless you have a clone you could restore from), I don't think you'd need to go that far.

While TRIM is a definite aid to the Garbage Collection routines which SSD controllers use, they can, over time get by without it. I'm a Crucial SSD fan and one of their suggestions is to allow some powered up quiet time for GC. With a Mac, a way to get that is to boot with the Option key down. This invokes the Startup Manager and while the connected bootable devices appear in a row, they aren't actually in use. I don't prefer that method only because things tend to get warm inside and I can't use smcFanControl to keep things cool.

BTW, another thing to consider is that the relocation of valid data before erasure has to go somewhere. SSD manufacturers provide "overprovisioning," often 7% of the available space, that's unavailable to the user but available to the SSD controller. If your drive is big enough and you don't need all of it's capacity, when you create the partition, you can leave some space free, and, again, while it's not available to you, it gets included in the overprovisioning space for use by the controller. For example, check out this review of the Samsung 840 EVO. You can compare the performance with the default overprovisioning and 25% OP.

thank you for your constructive information. however, as i'm just a layman and don't fully understand the whole process of GC.

i guess i'll just save the reformatting as my last option in any future events that my computers slows down. but thank you so much for the information!

i'm on day 2 with TRIM on now and everything seems fine.