SSD performance on a Macbook...

[Karel Bata]

I'm on the verge of buying a Macbook, and have been contemplating putting a SSD in. It seems like a good idea, but I'm worried by what I read about the drives Apple uses. First a little overview:

SSDs work by using NAND flash memory, which is actually very slow, but there is a lot of it and it runs in parallel, so the overall performance is very high. This is important - any data is distributed across the drive, not in clumps like on a HDD.

Users typically notice that an SSD drive runs at the manufacturer's stated peak I/O performance at first, but soon after that it begins to drop. That's because, unlike a hard disk drive, any write operation to an SSD requires not one step, but two: an erase followed by the write.

Also, when an SSD is new, the flash memory inside it has been pre-erased; Users start with a clean slate, so to speak. But, as data is written to the drive, data management algorithms in the controller begin to move that data around the flash memory in an operation known as wear-leveling. Even though wear-leveling is meant to prolong the life of the drive, it can eventually lead to performance issues.

That's still only a partial picture. SSD memory management is quite complicated. More info here http://www.anandtech.com/show/2738/8 You getting the gist?

When it happens it's quite a drastic reduction, but if you were using a decent drive like the OCZ Vertex (Intel is better but pricier) your SSD will start out at something like 15x the speed of an Apple HDD, so when it drops it'll be down to 10x. Still good.

BUT, unfortunately, from what I read, Apple's own SSDs appear to be made by Samsung. "On no, it says OCZ." you say. Uh oh. OCZ's Apex and Summit (the one Apple uses) use rebranded Samsung drives. Some tales of woe:

"My new SSD died" http://blogs.computerworld.com/my_new_ssd_died_dare_i_try_another It was an OCZ Apex.

"What's Wrong with Samsung?" http://www.anandtech.com/show/2829/19 Those test figures look terrible!

There's a lot of rubbish on the net about this from folk who should know better the limitations of their own knowledge. For instance there's a persistent myth about de-fragging, indicating a complete lack of understanding of how an SSD works. De-fragging (I'm pretty sure) would actually slow it down and even reduce the drive's lifespan!

Thoughts anyone...?

 

[Fredrik Callinggard]

I took out the optical drive and are running a 2 SSD OCZ Vertex drive RAID in mine. Blazing fast... as expected.

Working fine the last 6 months on one Macbook Pro. Another one had troubles in the start but that's all fixed and it's trouble free now.

I abuse my computers quite severely so they tend to break down eventually SSD or not, but I'm really happy with the choice of using OCZ Vertex drives - obviously it voids the warranty unless you change back to original configuration when you need to turn it in for repair.

 

[Uli Plank]

What do you expect from it? Better startup times?
You shouldn't work with footage on the internal drive anyway. Get a 17", a good e-SATA card and a small RAID, and you're in business.

 

[Fredrik Callinggard]

Have that too

 

[Fredrik Callinggard]

Ok seriously - Any application starts within more or less 2 secs. Literally just pops up. Scrolling in applications etc goes super quick, no lagging etc.

It's a great improvement that has to be lived to understand. It does of course take out the optical drive so you have to have external for that. It also gives a greater chance for drive failure, since it's a RAID0, BUT if you back up frequently that's fine.

Anyway, I'm happy with the OZC Vertex drives. They've served us well.

 

[Karel Bata]

Thanks for the replies.

Frederik, your config sounds great. Though having gone through a RAID 0 failure myself (only once in ten years, but recovering lost data on a failed RAID 0 setup is very difficult - and I didn't manage it) I'd be more inclined to either have RAID 1 (mirroring) , or else to have another boot option on the second drive ready for when (as it will eventually!) the first drive dies so I can immediately recover. Additionally, memory management on a regular SSD is really clunky, so I'm not sure that with a RAID 0 you're really getting the benefits you think you are.

Unfortunately your enthusiasm doesn't address my concerns about the re-branded Samsung drives that Apple uses - anyone here used those for a while?

How old is your Mac? One option for me is to buy an older Mac and add SSDs to that. That warrants a separate post methinks...

And here's another question - if you swap out the HDD for SSDs and the Mac itself fails, say the screen, could you get away with putting the HDD back and not owning up to ever taking it out? Can they tell? Anyone done similar - took it back under warranty whilst not owning up to a mod? :blink: