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TRIM Enabler, The Benchmark System, And Software

Aftermarket SSD On A MacBook Pro: TRIM Gets Tested
By , Achim Roos

Again, Apple supports TRIM through OS X, but only when you use one of its OEM drives. Swap out for something else and TRIM gets disabled. We've heard the horror stories about turning it back on through third-party utilities, which is why in our previous piece we did this the hard way:

"Fortunately, the restriction isn't hardwired. There's a bit of terminal window work to lift the Apple SSD requirement, but it's all covered in sufficient depth at Github."

This time, for brevity's sake, we went ahead and gave the TRIM Enabler app a try. It's about as easy to use as you might imagine. Slide a lever from left to right and you're good. Just be aware that operating system updates tend to reverse this process, so you'll need to repeat it if OS X gets patched.

Before TRIM Enabler can be used, the option to allow software installations from anywhere (and not just from the App Store and identified developers) needs to be set in the operating system's settings.

Benchmark System and Software

We're using a MacBook Pro for our benchmark system. To be more specific, it’s the smallest version of the eleventh generation that was introduced in mid-2012, also known as the MacBookPro9,2 model.

The notebook originally came with a 500 GB hard drive, which we took out and dropped into an external USB 3.0 enclosure. Samsung's 840 Pro SSD takes its place. We booted the system from the original hard drive.

Apple MacBook Pro
ModelMacBook Pro
Model Number
MacBookPro9,2
CPUIntel Core i5-3210M
CPU Clock Frequency
2.5 GHz
Number of Cores
2
L2 Cache (per Core)256 KB
Shared L3 Cache3 MB
RAM4 GB
System Hard Drive
Seagate ST500LM012 (500 GB; 5400 RPM)

Benchmark Software

We’re sending the Samsung 840 Pro SSD though two rounds of benchmarks. First, we perform a secure erase, which tells the controller to clear all blocks on the drive. This resets the SSD to the state it shipped in, yielding the best possible performance. We then complete the first round of benchmarks, which consists of running AJA System Test and DiskTester twice without TRIM. This provides a good comparison between fresh out of box and well-used performance.

For the second round, we perform another secure erase, and then we send it through the two benchmark passes with TRIM enabled. This gives us a total of four results:

  • TRIM disabled, first pass (brand new)
  • TRIM disabled, second pass (well used)
  • TRIM enabled, first pass (brand new)
  • TRIM enabled, second pass (well used)

A detailed account of a round of benchmarking:

  • Only for second round: Install TRIM Enabler and reboot MacBook Pro
  • Start AJA System Test benchmark (benchmark file size 16 GB)
  • Start DiskTester benchmark (block sizes 4 KB and 8 KB)
  • Have DiskTester fill entire SSD with data three times to simulate use
  • Fill entire SSD with video data
  • Take 30-minute break
  • Start AJA System Test benchmark (benchmark file size 16 GB)
  • Start DiskTester benchmark (block sizes 4 KB and 8 KB)

Display all 13 comments.
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  • 0 Hide
    osamabinrobot , July 25, 2013 9:38 PM
    i think you have an issue with your benchmark graphs, both trim enabled say fresh state
  • 0 Hide
    osamabinrobot , July 25, 2013 9:38 PM
    i think you have an issue with your benchmark graphs, both trim enabled say fresh state
  • 1 Hide
    steamingabe , July 25, 2013 11:10 PM
    Any chance you did any real world benchmarks with the stock 500gb drive as well as the 840 Pro?
  • 0 Hide
    halcyon , July 26, 2013 2:43 AM
    My hat is off to the author for the first 3 paragraphs, to say the least. I'm not sure where I've seen this more succinctly...more clearly explained.

    Ah, Apple. Why must it be a love-hate relationship? Clearly, you make some awesome hardware but your pricing and closed-mindedness is @$$munch. You disable TRIM if one doesn't pay 50 to 75% more for one of your lower-performing (than the typical aftermarket piece) OEM SSDs. Shame on you. Greedy bastards. Get with it or continue to decline. It's good to see in the case of TRIM Apple's @$$munchiness is so mindlessly circumvented. ...and to think I once gave them a bunch of my money. 4" Apple...4"
  • 0 Hide
    crisso2face , July 26, 2013 3:30 AM
    I wish it would be that easy. But its not. The problem with the OS X Trim command it that it kills your SSD. I fried 3 SSD Samsung 840 ( not the pro version ). Im at my 4-th right now ( thx God for warranty ). I work in a laptop store service. So I deal with a lot of laptops on a daily basis. This isn't my firs run in with SSD's. Cant really explain it, not an OS X expert. As soon as I turn on trim, with in a month or so, my SSD dies. This is my personal laptop. As I was saying, I work in a service, I have tech guys which are very good at what they do. If it were a motherboard problem, they would have found it. Its not the laptop ( MacBook Pro 17" Mid 2010 I5, nVidia 330M ). I can't really prove it, I my self, am a guy that needs hard proof, but this isn't a coincidence. 3 SSD's. I just recently had 2 customers with a macbook that asked me to upgrade to an SSD. They both came back to me in a month and a half with a fired SSD. After replacing them i hadn't turned on trim anymore. It's been 3 moths since, and they haven't returned since. Right now I myself use a 4-th SSD Samsung 840 without trim enabled. Haven't had a problem since. You do the math.
  • 0 Hide
    ojas , July 26, 2013 6:06 AM
    Hey, you know what i'd really like to see? How to enable TRIM/AHCI when you have a MacBook running Windows.

    I installed Windows directly, then performed some magic to install bootcamp drivers later, but the problem was that the EFI in Apple PCs disable AHCI when running Windows.

    Now Intel'ss SSD toolbox can still perform TRIM even when it's IDE mode (apparently) but i wasn't sure, so i had to Google a solution.

    Currently i have to enter four console commands in a GRUB menu before i can boot into Windows over AHCI, and BootCamp doesn't like it when i do.

    It's annoying, because i don't know much Linux, and i have no idea how to enable the GRUM menu or some sort of automated boot script that enters those commands for me.

    Commands:
    setpci -d 8086:2828 90.b=40
    set root=(hd0,1)
    chainloader +1
    boot
  • 1 Hide
    ssdpro , July 26, 2013 6:15 AM
    There is a big question here: Why does Apple intentionally disable TRIM on non-OEM drives? Think long term - why would Apple, who controls the testing/firmware on OEM storage, know they need to disable TRIM on all 3rd party drives? Are they preventing a problem that is exposed after long term usage of TRIM hacks with their EFI/SMC/OSX code?

    Look at crisso2faces comments above - I see that all the time on drives from multiple manufacturers, not just Samsung. Is seeing a couple extra MB/s in a benchmark worth gambling with possible catastrophic failure because you aren't using the system as designed?
  • -1 Hide
    TheCapulet , July 28, 2013 10:01 PM
    I agree with SSDPro. I know a lot of AppleCare Advisors, so I know first hand how terribly limited Apple Computers are. But the fact of the matter is... it simply comes down to this: If you want "advanced"(lol) features like TRIM support, don't buy an Apple computer.

    If you bought a Mac without doing research into your own required features, return it. If you're past your 15 days, look at it as a lesson learned. Macs aren't for everyone. Realistically, Macs aren't for anyone aside from people who want the most watered down experience possible, but the pro apps keep people in line for computers that don't really fit their needs.
  • 1 Hide
    crisso2face , July 29, 2013 6:53 AM
    The problem with trim on mac is that it has something to do with the comand it self that is sent from the OS X. From what I heard so far, it appears that the command is designed for a limited nr of drives. It has somthing to do with the timing and the blocks or cells of the SSD. The Trim comand of OS X is design for those specific drives. Repecing them with difrent 3rd party drives could prove catastrophic. I dont really understand how that works, up until now i bealived that the comand is basicly the same, no mater of the OS you use. As it turns out ( and i am not yet completely convinced of this ), the comand for trim is NOT the same for all OS's. Apparantly OS X tells the drive to do the trim in some different way, and that wers out the drive very very fast end eventually it dies out. Like I said. Im not an expert, but somthing obviously happens with the drives once you enable trim. Unfortunately I cant take the chance anymore.
  • 0 Hide
    rojjr , July 31, 2013 3:13 PM
    I am using a 256GB Samsung 830 Pro in a late 2011 iMac using TRIM enabler and I haven't had any problems in 8 months. Before I had this same drive in a 2009 iMac and it performed well also. *fingers crossed*
  • 0 Hide
    jameskatt , November 17, 2013 4:55 PM
    The biggest argument I have against enabling TRIM is that TRIM is a SATA-only command.

    SSDs attached via PCIe, USB 3.0, FireWire, or Thunderbolt cannot receive the TRIM command. Macs won't even recognize them as SSDs nor would the Mac send them the TRIM command even if it is enabled.

    The newest MacBooks now use PCIe SSDs.

    SSDs (such as OWC Mercury SSDs with SandForce controllers) have evolved to the point they don't need TRIM - particularly when the SSDs are not attached via SATA? They do their own garbage-collection and optimization.

    OWC - in particular - advises against enabling TRIM on their Sandforce controller OWC Mercury SSDs since this increases wear and tear on their SSDs. TRIM adds extra unnecessary writes when the SSD already did this on its own. Enabling TRIM would essentially harm the SSD and shorten its lifespan. http://blog.macsales.com/11051-to-trim-or-not-to-trim-owc-has-the-answer

    If modern SSDs need TRIM, they would be in danger of serious performance problems if the SSD was attached via a non-SATA connection such as USB 3.0 or PCIe or Firewire or Thunderbolt. Unless the manufacturer insures their SSD's controller does its own version of TRIM, then they would suffer serious performance problems when attached via non-SATA connection compared to the competition.

    This is why I argue that TRIM is currently useless in modern SSDs.
  • 0 Hide
    RobLewis , December 3, 2013 8:31 AM
    More modern systems may behave differently, but when I upgraded an early-2008 MacBook pro with a SATA I 256GB SSD from Kanguru, it worked great at first but got steadily slower and slower until I was considering putting the original hard drive back in. Trim Enabler completely turned the situation around and the SSD is back to being as snappy as ever.
  • 0 Hide
    RobLewis , December 3, 2013 11:28 PM
    More modern systems may behave differently, but when I upgraded an early-2008 MacBook pro with a SATA I 256GB SSD from Kanguru, it worked great at first but got steadily slower and slower until I was considering putting the original hard drive back in. Trim Enabler completely turned the situation around and the SSD is back to being as snappy as ever.