How do I choose a SSD ?

[dmegatool]

So I'll be buying a 13" MBP like this week/tomorrow. I want to replace the SuperDrive with a SSD but I'm kind of confuse with all the specs, controllers and all. What matter the most, IOPS or max sequential read/write ?

I looked that one : Intel 335, 240GB 193$ (http://www.newegg.ca/Product/Product.aspx?Item=N82E16820167128) (not much specs there though, can see more there: benchmarkreviews.com (http://benchmarkreviews.com/index.php?option=com_content&task=view&id=930&Itemid=60)). Is that a good drive ? I'm not looking for the absolute fastest out there but you know... don't want the slowest either. The $/Gb is interresting. Lots of good review about the 330 serie. the 335 is faster though.

Or will I notice the speed increase with something like a Vertex 4 ? : Vertex 4, 256GB, 230$ (http://www.newegg.ca/Product/Product.aspx?Item=N82E16820227792). That's 40$ more...

Also, what's the Trim function doing exactly ? Will OSX support it or am I wrong to think it's enabled for Apple installed disk only ?

[Wraven]

Google OWC. You will be glad you did.

[nikstar101]

Yeah MAc OS X will only officially support TRIM for Apple installed SSD, which is a right pain. After looking on MacRumors there is an unofficial TRIM installer that seems to work very well. Although i understand you should not install it on Sandforce controllers (like OWCs and Vertex).

To be honest they all are quite good these days, each manufacturer and model seems to have there own little niggles but in most cases they all are now reliable.

[dmegatool]

Yeah seems like people are getting mixed results when manually enabling trim. Wonder if I should bother and if it's worth it...

BTW I just ordered my 13" refurb MBP. That's the one release in June 2012... 1019$ (saved 180$). I'm happy. The thing will fly with the SSD :)

[Maciej]

http://www.storagereview.com/best_drives

I think Anand from AnandTech recommends the Samsung drive found in that Leaderboard for Mac users, but I could be wrong. I think it'll probably be a-horse-a-piece if you go with anything in the performance category.

[drewprops]

What is the advantage of trim in regard to SSD controllers?


...

[dmegatool]

Don't know, but would like to.

[FFL]

Google OWC. You will be glad you did.

++

http://eshop.macsales.com/shop/SSD/OWC/Mercury_6G/

Good prices, best-rated product performance, and developed/tested for maximum Mac compatibility. And the drive has its own TRIM equivalent built-in. And you can add their DataDoubler product for optical bay installation for a discounted bundle.

If you pay a few dollars more for one of these than a generic brand, it's money well spent.

[drewprops]

Trim, people, TRIM!!!!

TEACH ME ABOUT TEH TRIM!!!!

Don't make me Google it.


...

[FFL]

TRIM?

Stands for Totally Real In your Mind, I believe.



;)

[Dorian Gray]

I recently ordered a 750 GB Hitachi Travelstar 7K750 for my Mac mini (after first getting (http://forums.applenova.com/showthread.php?t=36887) a 750 GB Western Digital Scorpio Black six months ago. Great performance, but way too noisy for constant running as the boot drive).

This TRIM confusion, and the sheer fussiness of SSDs when keeping them at top performance, were major reasons I opted for a disk. Garbage collection, wear levelling, write amplification, firmware glitches: I can’t be bothered. For the price of these SSDs, you’d think they’d just work by now. Maybe next year?

[FFL]

This TRIM confusion, and the sheer fussiness of SSDs when keeping them at top performance, were major reasons I opted for a disk. Garbage collection, wear levelling, write amplification, firmware glitches: I can’t be bothered. For the price of these SSDs, you’d think they’d just work by now. Maybe next year?

My Thunderbolt MBP 15 has a OWC 480 SSD for 18 months, and my 5-year-old iMac is rockin' a OWC 115 SSD as its boot drive for over a year. Not a lick of trouble with those, nor from my dozen or so clients I've installed them for in the last couple of years. I consider them more reliable and less fussy than an HDD, and even if they are not "kept at top performance" they are multiple times faster than an HDD that is.

[chucker]

TRIM is a command in which the operating system tells the drive that it doesn't need certain data any more. This may seem like an obvious, important operation, but with magnetic hard disks, the opposite strategy has always been more useful: the OS just stores the fact that the file is no longer needed in the file system's directory; the file itself is untouched and effectively just quietly abandoned. This is great for performance, as the hard disk doesn't have to overwrite all the sectors the file had. Because of the different way SSDs structure their data internally, however, this strategy eventually leads to performance degradation. So now, the OS tells the SSD which sectors it doesn't need any more, and the SSD's controller decides how to optimize for that new piece of information.

TL;DR: without TRIM, performance on SSDs tends to degrade significantly; TRIM mitigates this.

[drewprops]

Okay that makes sense and sounds vaguely familiar.

Thank you Chucker.

I just did a search to see if Other World Computing, which is aggressive in the Mac upgrade market, has anything to say about TRIM.

I found this Customer Review from last February. (http://blog.macsales.com/13280-review-mercury-extreme-pro-6g-ssd-in-macbook-pro#more-13280)

This user added a 480GB SSD to a machine like mine (an early 2011 MBP) and recovered the contents of the previous drive from a Time Machine backup.

Here's a quote by the customer regarding TRIM:

My MacBook Pro supports 6Gb/s SATA out of the box, and although the System Profiler does not show TRIM support, this is not an issue, as the OWC SSDs have TRIM support built-in.

I should read up on OWC's SSD page, but I have to assume this means TRIM handling is in on-board firmware on the SSD as opposed to being an OS thing. (?)

Just curious:

Which configuration is more common: swapping SSD for existing hard drive or removing CD drive and adding SSD in addition to the existing hard drive?




...

[Dorian Gray]

Thanks, chucker. Two questions:

is it true that TRIM is never supported for third-party SSDs under OS X, and if so, is the hack to enable it advisable?
do you have an SSD in your personal computer?

[SpecMode]

To add to the TRIM discussion: some drives have garbage collection built-in to the drive's onboard controller that handles garbage collection in mostly the same way that TRIM does (basically, GC is handled at the hardware level rather than by the OS).

OWC's drives are based on SandForce controllers that have this feature available; the company specifically recommends not enabling TRIM (http://blog.macsales.com/11051-to-trim-or-not-to-trim-owc-has-the-answer) for their drives, as it could (in theory) compromise performance and reliability due to duplication of garbage collection functions.

For the record, I'm using a Mercury Electra 6G 120GB drive in my MacBook Pro, and it's been running just fine (without TRIM) for well over a year now.


is it true that TRIM is never supported for third-party SSDs under OS X, and if so, is the hack to enable it advisable?


Correct: TRIM is not supported for non-OEM SSDs under OS X. I would recommend enabling it for drives without built-in garbage collection (you'd probably need to do a bit of research for non-SandForce drives to find out if they have it onboard or not).

[GSpotter]

I have Samsung 830 512GB drive in my new MacBook Pro and a Samsung 830 256GB in my company PC notebook (which I have now for about a year). So far no problems and great performance. The Samsungs also have a track record of being rather reliable. You might get some good deals, as the successor generation is already available (840 and 840pro).
I enabled TRIM on my SSD with the Trim Enabler app.

I also have a Crucial M4 128GB which I had in my old MacPro. So far also no problems, but Crucial had updated the firmware several times and updating is a bit of a hassle.

[Maciej]

Here (http://www.anandtech.com/show/2738) is a great article from AnandTech describing how an SSD works and why TRIM is necessary.

I would definitely suggest against enabling TRIM on SandForce based drives, at least in my experience it has lead to stability issues on my Vertex 3 system.

[chucker]

I just did a search to see if Other World Computing, which is aggressive in the Mac upgrade market, has anything to say about TRIM.

I found this Customer Review from last February. (http://blog.macsales.com/13280-review-mercury-extreme-pro-6g-ssd-in-macbook-pro#more-13280)

This user added a 480GB SSD to a machine like mine (an early 2011 MBP) and recovered the contents of the previous drive from a Time Machine backup.

Here's a quote by the customer regarding TRIM:



I should read up on OWC's SSD page, but I have to assume this means TRIM handling is in on-board firmware on the SSD as opposed to being an OS thing. (?)

No, TRIM has to be supported both by the SSD's firmware (to interpret the command) and the OS (to send it in the first place).

Thanks, chucker. Two questions:

is it true that TRIM is never supported for third-party SSDs under OS X, and if so, is the hack to enable it advisable?
do you have an SSD in your personal computer?


OS X's TRIM support by default is limited to certain SSDs — mostly (or all?) Apple-branded ones. The patch simply disables this limitation. As for whether Apple put in this limit to generate more revenue or because they haven't had a chance to test it thoroughly with third-party SSDs and have actual concerns, only they can answer that.

I don't have an SSD.

To add to the TRIM discussion: some drives have garbage collection built-in to the drive's onboard controller that handles garbage collection in mostly the same way that TRIM does (basically, GC is handled at the hardware level rather than by the OS).

Ah, but TRIM is essentially a command that helps the SSD know when garbage collection is a good idea.

I'd be curious how an SSD's controller would know this well otherwise (other than through least frequently used / least recently used mechanisms?), especially if encryption is active. They're too low-level to understand the concept of a file, much less whether it still ought to be accessible.

[Maciej]

I'd be curious how an SSD's controller would know this well otherwise (other than through least frequently used / least recently used mechanisms?), especially if encryption is active. They're too low-level to understand the concept of a file, much less whether it still ought to be accessible.

I have always understood that controller "prompted" garbage collection, ie. not TRIM, happens at times of low/no IO - for example in the middle of the night. That is why it has been commonly recommended to let the computer idle, not sleep/suspend.

Edit: but now I'm having trouble finding this info online, so actually I might be wrong. In fact, I'm seeing that early model SandForce controllers had problems with sleep, as in it induced bricking. So now I'm not really sure. What I distantly recall is that idling the computer was recommended in the early days, now I can't find that info. Sorry!

[chucker]

I have always understood that controller "prompted" garbage collection, ie. not TRIM, happens at times of low/no IO - for example in the middle of the night. That is why it has been commonly recommended to let the computer idle, not sleep/suspend.

That doesn't change that the SSD won't know well what garbage to collect; the OS combined with the SSD would know far better.