June 26, 2013 6:50 PM   Subscribe

I would like to upgrade the harddrives on my dad's 2008 macbook pro and my wife's 2010 macbook to SSD. I have questions?

Both are running Mountain Lion.

I'm thinking about getting crucial SSD drives; but I'm concerned about their long term performance. I understand Mountain Lion has TRIM support, but Crucial SSD's also have garbage collection? And these work together, and so you should have both? Or they don't, and using both will ruin everything? I be confused.

If there be other warnings regarding the use of third party SSD's in apple laptops, I'd love to hear them.
posted by deliquescent to Computers & Internet (16 answers total) 5 users marked this as a favorite
I have used Intel SSDs to upgrade 2007 and 2008 MBPs with no ill effects, and notable speed and noise reduction improvements. I use Trim Enabler with these drives.
posted by Blazecock Pileon at 6:57 PM on June 26, 2013 [1 favorite]

You don't need to buy super fast drives, buy the cheaper larger capacity ones. At best those generation of machines will support SATAII limiting you to 300mbs throughput, at worst SATAI - aka 150mbps land.

In general, trim support was so poorly implemented and then mangled by the operating systems that many if not all drives have built in garbage collection in the controllers. You can enable it if you want on osx but if the drive supports onboard garbage collection don't bother.

It is likely/possible you will not be able to update the firmware on the drives under osx as many drive manufacturers have not come out with an osx specific tool to update. This can mean you have to remove the drive and attach it to a windows box OR that a live cd must be booted. My experience has been hit and miss.
posted by iamabot at 7:20 PM on June 26, 2013

I work for an OEM that uses SSDs for operating systems. Intel and Kingston yes, Transcend HELL NO. At home, I run a Crucial that I'm happy with-- it replaced an OCZ that crapped out on my, but I think I've gotten the idea that OCZ has gotten it together. Anyway, Just say no to Transcend for OS SSD. On balance, I'd go with Intel or Crucial.

If you're so inclined, you can buy gadgets to replace your optical drive in your MBPs with a second drive, for storage. Optibay is an example of such a product; I've not yet used one, so I can't endorse or condemn this brand.

Since space on an SSD is comparatively premium, I recommend having a second drive and using either symbolic links to the second drive, or simply install things on the second drive that don't require the loading speed, or that do take a lot of space.
posted by Sunburnt at 8:05 PM on June 26, 2013 [1 favorite]

Best answer: Yes, TRIM and garbage collection complement each other. TRIM is the only way a controller knows in advance that a block has been erased by the OS and no longer needed. This is because the OS does not physically delete an unused block. It just writes a bit in a file table to indicate that the block is deleted. The disk controller does not (generally) have direct knowledge of where the OS keeps its file tables or what the bits mean, so it has no ideal that a block was just deleted. Instead it has to wait for the OS to issue a command to overwrite a logical block. When the OS overwrites a block, the disk controller can infer that the block can be physically deleted. But in that case, the disk controller has to pause to erase the block and that slows throughput.

The TRIM command from the OS gives the disk controller a heads up to deleted blocks and the disk controller can arrange to erase that block when the system is idle, removing potential write delays.

Garbage collection has to free up blocks using less information. I moves small blocks around in order to free up larger groups of erased blocks. But without the TRIM command, garbage collection will have to move and rewrite some blocks that the OS has marked for deletion but the disk controller doesn't know about because the OS hasn't yet ordered an overwrite for the block. This means that garbage collection alone will do more rewrites of unnecessary data, reducing the life of the memory.

So the bottom line is that TRIM and garbage collect work hand in hand to more efficiently manage the disk and increase disk lifespan by reducing unnecessary copy and writes.
posted by JackFlash at 8:12 PM on June 26, 2013 [1 favorite]

Response by poster: Thanks all... More questions:

Blazecock Pileon - is TRIM enabler still necessary in mountain lion? I thought ML had built-in TRIM support?

iamabot - the upgrades are less for space and more for speed; is there a way to tell which SATA each machine has (my google skills have failed me, and DiskUtility just lists "SATA" just like on my 2011 MBP")?

Sunburnt - Crucial seems to have good reviews, esp after a firmware update a year or so back, and good prices so i'm leaning towards them

JackFlash - thanks so much; that seems consistent with a better blog post (now lost to me) I read on the topic. There is a lot of contradictory information out there.
posted by deliquescent at 9:08 PM on June 26, 2013

Somewhat of a sidetrack, but just for the heck of it: I put an SSD in my Macbook when I bought it and set it up by just dragging over the existing System folder from the original drive. Much later I tried to turn on FileVault, and discovered I couldn't do that without reinstalling OS X: if you don't do a from-scratch install, the OS X Recovery partition is not created. (And FileVault will refuse to work without it.)

posted by mvd at 3:52 AM on June 27, 2013

I've got an SSD in a 2007 MacBook running 10.6.8. The performance upgrade is like having a whole new computer, but it does have random short freezes (10-20 seconds, display still refreshes but nothing else does) now and then that I suspect are due to some sort of incompatibility between the older MacBooks and SSDs. I don't really care because the trade-off in speed is so good, and it doesn't annoy me enough that I've tried to solve the problem. YMMV on whether that's an acceptable downside, though.
posted by asperity at 5:50 AM on June 27, 2013

Very happy that I replaced the optical drive in my 2009 MBP with a 60GB SSD for the OS, and a 640GB conventional drive for storage via OWC. Added an external enclosure for the SuperDrive and all's been well since. OWC also have excellent video tutorials on opening up the machine and making the swap.
posted by omnidrew at 6:31 AM on June 27, 2013

To find your SATA speed:

Apple Menu > About This Mac > More Info > Hardware > Serial ATA > Link Speed
posted by doctord at 6:41 AM on June 27, 2013 [1 favorite]

I have a Crucial m4 256G drive as my primary drive on my early 2011 MBP. It runs fine and makes this machine faster for most operations than my desktop iMac. So far the only downside I've found is that updating the firmware while installed on the mac is impossible. Update that on a PC before you install it.

You need the TRIM enabler. The OS supports TRIM but only on Apple's SSD drives. The trim enabler removes the check that rejects other manufacturer's drives.

Also, SATA speed is sort of irrelevant. Your big win is there is no seek time for SSDs. Just IMHO.
posted by chairface at 9:16 AM on June 27, 2013 [1 favorite]

Best answer: You don't need to buy super fast drives, buy the cheaper larger capacity ones. At best those generation of machines will support SATAII limiting you to 300mbs throughput, at worst SATAI - aka 150mbps land.

Your numbers are low by a factor of 10x. Furthermore, those numbers are for sequential reads and writes, and one of the beautiful things about SSDs are their random I/O performance, which may be constrained by slower SATA buses, but not nearly to such a degree.

Still, it is true that super-fast drives aren't that important in older machines. I wouldn't just go by older drives though, because newer generations often have better random I/O performance, power consumption, and performance consistency (due to better garbage collection).

As for what SATA version the OPs computers have, run System Information and look in the Serial-ATA section. On my (newer) MacBook Pro, it lists a link speed of 6Gigabit (SATA 3).

One thing to look out for, apparently some SATA2 Macs had issues where they'd end up only negotiating 1.5Gbps speeds when hooked to SATA3 devices, instead of the expected 3Gbps. Whether that is an issue for you, I can't say.
posted by Good Brain at 11:03 AM on June 27, 2013 [1 favorite]

Your numbers are low by a factor of 10x

Depends how you read them. Drive throughput speeds are usually quoted in megabytes per second; interface speeds in megabits per second. And although a byte is eight bits, not ten, assorted overheads mean that if the interface is the bottleneck, the maximum achievable byte throughput rate will generally be roughly a tenth of the interface bit rate.
posted by flabdablet at 10:30 PM on June 27, 2013

Drive throughput speeds are usually quoted in megabytes per second; interface speeds in megabits per second

Yes, but if one is going to give abbreviations for throughput, then it is customary to write "B" for bytes and "b" for bits.
posted by Good Brain at 10:40 PM on June 28, 2013

Fair point. On the other hand, pedantic insistence on correct case would make "150mbps" too low by a factor of ten billion :-)
posted by flabdablet at 12:19 AM on June 29, 2013

Chiming in to say I've also done what omnidrew and Sunburnt mentioned and replaced the optical drive with an adaptor from OWC that lets you put a regular disk drive in there. Works great. I installed a 1 GB disk and partitioned it such that part was used for mirroring the main disk to a bootable partition, and the rest was for extra storage. I used Carbon Copy Cloner to set up a daily task to mirror the contents.

I have a paranoid fear of the SSD failing unexpectedly. Since non-SSD disks are so cheap now, a 1GB disk is not much more expensive than a lower-capacity one, and the extra insurance against a failure makes it a good investment for me.
posted by StrawberryPie at 6:25 AM on June 29, 2013 [1 favorite]

Response by poster: Thanks everyone; I put in a crucial M500 drive, activated TRIM, and everything worked fine. There was some setting I had to change to get it to boot as quickly as possible - I forget what - but otherwise smooth as silk. Oh, and I was flipped out when Verify Disk returned a whole mess of errors, but it ran smoothly when I checked it Recovery Mode, so not quite sure what that's about but I figure it's something about the way the OS deals with the new SSD, not anything bad. Anyway, thanks all for the great advice!
posted by deliquescent at 8:59 AM on August 4, 2013

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