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bkfraiders7 Level 1 (0 points)
I am about to purchase my first Mac and Im so excited. But before I do I have a question about the SSD. I was not planning on buying the SSD, but instead just going to some 7200RPM HDD but realized the price was only an additional $90, a price you can not just go out and buy one at.

My only concern is the lack of TRIM in Mac OSX. Now, their is speculation (and partial proof) that Lion will have TRIM support, but from what I have researched TRIM is also a hardware variable and not just software. Does anyone know if the new MacBook Pro's SSDs offer TRIM support? Also, will my SSD, by Summer hopefully, be negatively effected by the few months of the lack of TRIM?

Thank you so much,


Macbook Pro (Early 2011), Mac OS X (10.6.6)
  • johnsock Level 1 (60 points)
    I think the only way to tell right now is to install a TRIM enabled operating system on your new SSD. This could be done with Windows 7, but might not be something you are willing or able to do. You could also open up the case and see what type of SSD is in there and then check the manufacturer specs for it.
    At any rate, I wouldn't worry too much about TRIM support at this time. TRIM has definitely proven to be beneficial with certain drives, but many of the newer ones work fine without it. I've been using SSD in my macs for a few years now and had no issues. Some of the drives (Intel X25-E) don't support TRIM at all, and the newer ones (OWC) support TRIM at the drive level but haven't ever used it since OS X doesn't currently support it. I assume that OS X will eventually support TRIM (judging from articles I've read) and compatible drives will use it. The Sandforce based SSD (like OWC) don't really need TRIM, but can use it where the Intel X25-M G2 drives benefit quite a bit from TRIM when it's supported by the operating system. I think we will know more once we figure out what drives Apple is shipping with the new MBP models.
    If you want to read up on SSD technology, check out the articles by Allyn Malventano on PC Perspective ( It's mainly a PC site, but the information is very good. DISCLAIMER: Allyn is a good friend of mine and we have been collaborating on a piece about SSD performance in BootCamp on the MacBook Pro.
  • EllaM Level 1 (5 points)
    I'm in your shoes (although looking for a replacement, not first purchase) and have similar questions. Since TRIM isn't supported by Snow Leopard, we know the SSDs wouldn't be getting "clean up" commands from the OS. Are these SSDs equipped to support the TRIM command should LION be installed? Is there some utility or other form of "garbage collection" in place RIGHT NOW? There seems to be a lot of disagreement as to how much degradation one might expect using an SSD without TRIM support, so I'm wary of purchasing it now. Some have suggested buying it with the standard hard drive and putting in a third-party SSD on your own after LION is released, but even that's not ideal because we don't know whether TRIM support will be extended to third-party SSDs. Plus, are third-party SSDs covered under AppleCare? Probably not, so...there's no clear answer as I can see.

    Sorry, I've answered your question with more questions. Anyone else have more knowledge about the state of the current SSD drives?
  • bkfraiders7 Level 1 (0 points)
    EXACTLY! I mean, the 128GB SSD is only a $90 upgrade which is unbeatable in the market. Instead of using the standard drive and buying a SSD, I instead could save that money and go the MCE route and buy a kit to replace the Super Drive with a 500GB hard drive for like $150 (instead of buying the kit+ SSD for like $300)
  • WWink Level 1 (0 points)
    If you buy one of the new 2011 MBPs, then from what I've read at AI,, TRIM is enabled. Caveat - The feature reportedly only supports Apple-bundled SSD volumes, but this may change as well.
  • wonslung Level 1 (0 points)
    I can confirm that trim support is included. I ordered my 2011 Macbook Pro the day they came out. I ordered the 128 gb ssd and was delighted to find trim support. Also seems to be sporting a new kernel ( 10.7.1 )
  • Jason Browdy Level 1 (25 points)
    I will also confirm TRIM is supported in the SSD I bought from Apple in my new 13" MBP. That said, I have been reading as much as I can on TRIM, including the Wikipedia article. But, I cannot seem to figure out if TRIM support in the OS means that the hard drive is being "cleaned up" in the background, and no action by the user is needed, or if I need to run a Unix command or something to do it manually. Sorry for the dumb question.
  • jimthing Level 1 (55 points)
    I had the same idea from a couple of weeks ago on a dual-drives set-up! See here:

    Is this TRIM issue the same as 'degradation of speed' that I've heard about with apparently *all* SSD's?

    Hence interested for views on the OWC "Extreme Pro" SSD's, as they make a couple of claims.

    • Firstly, they claim their SSD's suffer NO 'degradation of speed'. See from 2:50 here:
    Is this really true, as I thought *all* SSD drives do? Views please.

    • Secondly they claim "upto 7% over-provisioning" using Sandforce controllers filmware on their standard range (28% on the higher RAID-enabled range). What does this mean, is it important? See from 0:30 here:

    Anybody got any opinions on the OWC range, welcomed...
  • jimthing Level 1 (55 points)

  • johnsock Level 1 (60 points)
    You do not need to run any UNIX (or any other) programs to 'TRIM' the drive. If the drive firmware supports TRIM (as all newer drives do) and the operating system supports the TRIM command, you will benefit from this feature. The way TRIM works is this:

    When you delete a file from a drive, the operating system marks the space used by the file as free so it can be used again. On a mechanical hard drive this works fine and the space will get written over as needed. Unfortunately, the SSD does not know the difference between erasing a block and writing over it with new data, so they are treated the same. The problem that occurs with SSD is that each block on the drive has a limited number of write cycles it can withstand before failing so the SSD firmware tries to spread out the usage of blocks on the drive by a process called wear-levelling. This ensures that the drives last as long as they need to, but results in fragmentation of the drive. This is a lower level fragmentation than what is typically referred to when discussing hard drive fragmentation and is not really related. This low level fragmentation can result in reduced performance of the drive over time, as blocks are erased and data is moved around by the wear-levelling.
    The drive manufacturers have worked wonders trying to minimize this effect with intelligent firmware, but it is still a measurable problem. This is where TRIM comes into play. If the TRIM command (a low level drive command, not something you run from within the operating system) is supported throughout the system, deleting of a file will cause the operating system to issue TRIM to the SSD instead of just marking the blocks as empty as would be done on a mechanical hard disk. The SSD then knows that these blocks are no longer needed and the drive firmware can then clean up more efficiently. The drive firmware will show the space as available (because it is) but will not actually perform a write to that part of the drive until a later time, when enough blocks are ready to be TRIM'd all at once. This works in conjunction with the wear leveling to reduce wear on the flash cells and prevent fragmentation from occurring. For a more detailed description of TRIM, I recommend checking out the articles by Allyn Malventano over at PC Perspective:
    That site is mostly geared towards Windows users, but the basics of SSD operation are the same, and Allyn is definitely an expert when it comes to storage technology.

    As far as over-provisioning goes, this provides a way to reduce fragmentation without the need for TRIM support (although the SandForce drives also can do TRIM). Over-provisioning involves setting aside a certain amount of flash memory on the SSD (7-28% typically) that is not available (or visible) to the operating system. The firmware uses this extra storage space to more efficiently defragment and wear-level the drive and it is transparent to the operating system. This is why an Intel X25 G2 drive will benefit more from TRIM support than a SandForce based drive like the OWC or Vertex series ones. The above mentioned site also has some good articles about over-provisioning, including comparisons of the same drive with 7% and 28% overhead. It boils down to this: if you have a SandForce drive, TRIM support is not as important because the drive does a good job on its own. If you use a different SSD, TRIM support is very beneficial, and we should all hope that OS X delivers full support for TRIM in the near future. Also, the added expense for the enterprise level (28% over-provisioned) SandForce drives is normally not justified, especially in a single drive setup.
  • Zebra1 Level 2 (290 points)
    Trim support not enabled in 2010 Macbook Pros with just released 10.6.7.
  • Jason Browdy Level 1 (25 points)
    Thanks. That's possibly the most complete response I have ever gotten on a forum. Do you mind answering a few followup questions?

    I attached a screenshot of my information from About This Mac, indicating there is TRIM support. I have 10.6.6. Can I assume that TRIM is currently active? If not, assuming it is supported in Lion, is there something I need to do to go back and "clean up" the drive? If it is currently being used, is it safe to use my machine like I would any other machine with a standard hard drive? I have read that you should avoid a number of things in a SSD such as putting large apps on it, adding and deleting files, especially large media files, etc.

    In other words, is it safe to assume the TRIM will keep my machine working well for several years even if I use it as though it were a standard hard drive?

    Thanks again for your very helpful response.
  • Jason Browdy Level 1 (25 points)
    Sorry, I don't see a way to attach a screen shot.
  • johnsock Level 1 (60 points)
    Jason, glad I could be of some help. Unfortunately I haven't figured out how to post screenshots either...

    Your new MacBook Pro with Apple branded SSD does, in fact, support TRIM out of the box. There is nothing else you need to do other than use your new drive and enjoy. Unfortunately, it appears that Apple is not enabling TRIM support on 3rd party drives at this time, but hopefully this will change in the future. There are people looking into it at this time, so maybe there will be a non-sanctioned solution soon.

    As far as taking any precautions when using your new SSD, don't worry about changing how you operate. You can use the drive just as you would any other without fear. The one thing that you should not do with a SSD is run a defragmentation utility on it. This is not normally an issue in OS X, but is a common practice in Windows. Defragmentation utilities rearrange files on the disk at the file system level, resulting in a large number of reads and writes. On a mechanical hard disk, this is helpful for improving seek times, but on a SSD this just makes the drive's built-in wear-leveling and garbage collection work much harder, without any real benefit from a user standpoint. This is because the operating system is fooled into knowing the location of a file on a SSD, but where it thinks the file is located compared to it's actual location in flash are completely unrelated. The drive's firmware puts data where it needs to go and can find it when needed, unlike a mechanical disk where the physical location of your data has a real impact on the time it takes to retrieve it due to physically having to seek the disk. I've had SSD in my Macs for a few years now and never had any issues. The original Intel drive would experience some degradation in speed after using it for a while, but it was still MUCH faster than any hard drive. I'm currently running two OWC SandForce drives in my MacBook Pro and they are awesome. The new batch of drives that Apple is shipping may not be as fast as those with the SandForce controller, but they are still a vast improvement over what was previously available.
    I hope this helps. Feel free to ask anything else that comes to mind.
  • macmandanny Level 1 (0 points)
    I can 100% confirm TRIM IS NOT NEEDED on SandForce Based SSD's a number of performance tests done by myself (to satisfy me) and countless others on the Net have proved this time and time again.

    The Drive does its own Garbage Collection, left idling for 1 - 3hr GC kicks in, in my experience leaving my MBP sitting for an hour sorts itself out.

    This is using a 240Gb Vertex2E
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