7 ms·

Not only that. I've been a Mac user for almost 10 years now but I'm waiting for them to add TRIM support to OS X before taking the SSD plunge. Everybody using a

Not only that. I've been a Mac user for almost 10 years now but I'm waiting for them to add TRIM support to OS X before taking the SSD plunge. Everybody using an SSD on OS X should understand that its performance will degrade more quickly than on another modern OS. It's quite disappointing to me.

generalk 17y ago
For those curious as to why performance will degrade quicker on OS X: http://en.wikipedia.org/wiki/TRIM http://en.wikipedia.org/wiki/TRIM Just had to look that up myself. Shocking that OS X doesn't support it natively, although the article suggests there may be utilities that can replace that functionality.
- enterneo 17y ago
  Intel X-25M has TRIM support in the controller itself, and thats the way it should be I believe
  - sorbits 17y ago
    The drive does not know when data stored on the drive is “deleted”. This is what TRIM is for, i.e. when you delete a file you just unlink the inode. You need to tell the drive that the blocks that the file occupied are no longer needed, so the disk can ignore that data when reorganizing or later rewriting part of the block.
  - 9oliYQjP 17y ago
    Unfortunately while there are strategies to mitigate the problem in hardware, proper TRIM support is still best. You might be getting confused by the TRIM enabled firmware that was released in December '09 for that SSD? It just means that the Intel drive will obey TRIM commands from the OS. But if the OS doesn't send any commands, which OS X won't, then you're not taking advantage of TRIM. For what it's worth, if you were going to choose a drive that would degrade the least in performance without the use of TRIM, you probably chose best with the Intel X-25M. But it would still perform better over time in Linux or Windows 7.
- deleted 17y ago
  [deleted]
  - dedward 17y ago
    Deleted my previous ignorant comment - I had it backwards. The idea behind TRIM is so the OS can tell the drive when a block is free, so the SSD can pro-actively erase it, which is something that otherwise slows down the write cycle if you are writing to a block that wasn't already clean. That's not something you can just magic into a drive.....
cpr 17y ago
I don't know about that. I've had this SSD-based 15" MBP since last fall, using it full-time, and it certainly hasn't fallen off any performance cliffs. So maybe this is more of a theoretical problem than a practical one?
- greghines 17y ago
  It depends on your usage patterns. Performance begins to degrade as soon as you've written an amount of data roughly equal to the SSD's total capacity. If you're not writing much data to the drive on a regular basis, then it'll take a while to hit that wall. But once you do, it's a significant drop in performance for most SSDs. And at that point, the only "fix" is to format the drive.
  - ubernostrum 17y ago
    as soon as you've written an amount of data roughly equal to the SSD's total capacity After eight months of heavy daily use, in which I'm quite certain I've achieved more than 256GB of total writes, I've seen... no change in performance. Still zippy and happy and writing just fine. Time for misguided hype based on anandtech's articles to go away now.
    - jrockway 17y ago
      As another datapoint, I had a laptop with a first-gen SSD and no TRIM or GC support. The performance hit a literal cliff; writes were fast one day, and the next day they were literally 300KiB/s. Download speeds were limited by disk write bandwidth, not network bandwidth! New SSD, writes are back up to 50MiB/s. (The divide might not be at the capacity of the disk; this was a 16GiB SSD with probably 20x that in writes.)
      - cpr 17y ago
        Well, after 6-7 months of heavy use on my MBP (easily past 128GB worth of writing, many times), Xbench says I'm getting 100MB/sec for just about all disk activity with 256K blocks.
sorbits 17y ago
To clarify: There are two writing speeds of an SSD, one when the block is empty and one when the block already has data, the latter is slower and TRIM support from the OS will allow the SSD to know about “dead data” so that it can reorganize data to optimize free blocks. I am using the first generation Intel SSD which doesn’t actually support such reorganization and isn’t noticeable affected by “being full” (as opposed to writing to the factory default empty state). I am also using Crucial SSD (with OS X) and that as well is magnitudes faster than my previous mechanical disk. So all in all, this degraded performance is blown a bit out of proportion and you are doing yourself a great disservice by holding out for TRIM support — to echo others: SSD was the best upgrade I added to my system. Edit: I am btw using SSDs with a desktop system. So I compare them with my previous 7200 RPM drives. For a laptop there is absolutely no doubt that you should go with an SSD (if you can afford it), TRIM support or not. For a desktop, I would still highly recommend it.
- 9oliYQjP 17y ago
  I totally agree if it's a choice between somewhat decent SSD (e.g., I'd probably avoid the Samsungs that Apple actually offers) or hard disk, go for SSD. I'm just disappointed that Apple hasn't yet enabled TRIM support. They apparently laid the groundwork for it in the kernel but haven't actually finished off the work. Every time they roll out new models, I check to see if they've actually enabled TRIM support in a point update of OS X but they haven't. They'll eventually have to as it's being rolled into the ATA specification.

generalk 17y ago

For those curious as to why performance will degrade quicker on OS X: http://en.wikipedia.org/wiki/TRIM http://en.wikipedia.org/wiki/TRIM Just had to look that up myself. Shocking that OS X doesn't support it natively, although the article suggests there may be utilities that can replace that functionality.

enterneo 17y ago
Intel X-25M has TRIM support in the controller itself, and thats the way it should be I believe
- sorbits 17y ago
  The drive does not know when data stored on the drive is “deleted”. This is what TRIM is for, i.e. when you delete a file you just unlink the inode. You need to tell the drive that the blocks that the file occupied are no longer needed, so the disk can ignore that data when reorganizing or later rewriting part of the block.
- 9oliYQjP 17y ago
  Unfortunately while there are strategies to mitigate the problem in hardware, proper TRIM support is still best. You might be getting confused by the TRIM enabled firmware that was released in December '09 for that SSD? It just means that the Intel drive will obey TRIM commands from the OS. But if the OS doesn't send any commands, which OS X won't, then you're not taking advantage of TRIM. For what it's worth, if you were going to choose a drive that would degrade the least in performance without the use of TRIM, you probably chose best with the Intel X-25M. But it would still perform better over time in Linux or Windows 7.
deleted 17y ago
[deleted]
- dedward 17y ago
  Deleted my previous ignorant comment - I had it backwards. The idea behind TRIM is so the OS can tell the drive when a block is free, so the SSD can pro-actively erase it, which is something that otherwise slows down the write cycle if you are writing to a block that wasn't already clean. That's not something you can just magic into a drive.....

cpr 17y ago

I don't know about that. I've had this SSD-based 15" MBP since last fall, using it full-time, and it certainly hasn't fallen off any performance cliffs. So maybe this is more of a theoretical problem than a practical one?

greghines 17y ago
It depends on your usage patterns. Performance begins to degrade as soon as you've written an amount of data roughly equal to the SSD's total capacity. If you're not writing much data to the drive on a regular basis, then it'll take a while to hit that wall. But once you do, it's a significant drop in performance for most SSDs. And at that point, the only "fix" is to format the drive.
- ubernostrum 17y ago
  as soon as you've written an amount of data roughly equal to the SSD's total capacity After eight months of heavy daily use, in which I'm quite certain I've achieved more than 256GB of total writes, I've seen... no change in performance. Still zippy and happy and writing just fine. Time for misguided hype based on anandtech's articles to go away now.
  - jrockway 17y ago
    As another datapoint, I had a laptop with a first-gen SSD and no TRIM or GC support. The performance hit a literal cliff; writes were fast one day, and the next day they were literally 300KiB/s. Download speeds were limited by disk write bandwidth, not network bandwidth! New SSD, writes are back up to 50MiB/s. (The divide might not be at the capacity of the disk; this was a 16GiB SSD with probably 20x that in writes.)
    - cpr 17y ago
      Well, after 6-7 months of heavy use on my MBP (easily past 128GB worth of writing, many times), Xbench says I'm getting 100MB/sec for just about all disk activity with 256K blocks.

sorbits 17y ago

To clarify: There are two writing speeds of an SSD, one when the block is empty and one when the block already has data, the latter is slower and TRIM support from the OS will allow the SSD to know about “dead data” so that it can reorganize data to optimize free blocks. I am using the first generation Intel SSD which doesn’t actually support such reorganization and isn’t noticeable affected by “being full” (as opposed to writing to the factory default empty state). I am also using Crucial SSD (with OS X) and that as well is magnitudes faster than my previous mechanical disk. So all in all, this degraded performance is blown a bit out of proportion and you are doing yourself a great disservice by holding out for TRIM support — to echo others: SSD was the best upgrade I added to my system. Edit: I am btw using SSDs with a desktop system. So I compare them with my previous 7200 RPM drives. For a laptop there is absolutely no doubt that you should go with an SSD (if you can afford it), TRIM support or not. For a desktop, I would still highly recommend it.

9oliYQjP 17y ago
I totally agree if it's a choice between somewhat decent SSD (e.g., I'd probably avoid the Samsungs that Apple actually offers) or hard disk, go for SSD. I'm just disappointed that Apple hasn't yet enabled TRIM support. They apparently laid the groundwork for it in the kernel but haven't actually finished off the work. Every time they roll out new models, I check to see if they've actually enabled TRIM support in a point update of OS X but they haven't. They'll eventually have to as it's being rolled into the ATA specification.