Has my SSD died

SSD is dead.

By the way, what's the average life of SSDs? Is it similar to HDDs? Are they less reliable?

SSD is gone. SSDs are electrical and are more complex than a hard drive, so there is more to go wrong. They also have wear issues (more you write to them, the faster they wear out). MOST of the time, you can expect to get abotu 2-3 years out of an SSD, sometimes longer depending on how much use it gets.

Now, I can tell you this, out of ALL the MBA I have seen as a mac tech at my local AASP (about a year and 3 months now and we get about 400 apple machines a month), I can tell you I have only seen 4 MBA with SSDs come in that have failed.... I cannot even think of the number of hard drives I have to replace in that amount of time though. Its in the hundreds.

Macneck said:

By the way, what's the average life of SSDs? Is it similar to HDDs? Are they less reliable?

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Overall, while much more expensive, SSDs, due to their lack of physical wear & tear, in the conventional sense of the word anyway (more on that in a minute), are much more reliable than HDDs. You can check out HDDs' expected lifespans here: http://en.wikipedia.org/wiki/Hard_disk_drive_failure

Flash Memory lifespan depends on the amount of use, and as SSDs are still fairly new, most manufacturers of this type of memory are still gathering date on it's lifespan or MTBF. Common wisdom at the moment seems to be about 10,000 erase/write cycles for the MLC type of chips. (Multi-Level Cell, the most commonly used consumer type of SSD chips - There is also an SLC type of flash memory - Single-Level Cell -, which lasts longer, but is about three times the price of the MLC type; it is mainly used in Enterprise grade SSDs)

The reason SSDs wear out over time, despite there not being any 'conventional' physical wear & tear, is that the cells that make up the chips, have a tendency to hold on to the 'state', 1 or 0, that they are assigned, at any given write cycle; This 'memory' gradually gets stronger after every erase/write cycle, until it becomes so strong that the cell's 'state' can not be changed any longer, at which time your SSD will fail. This is the reason, reading from the SSD, does not significantly affect it's lifespan, just the erase/write cycles, and this fact plus the blazingly fast access times of SSDs are why the latter are such a no-brainer for holding your OS and assorted software and programs. Check out the boot-time comparisons of a mid-2011 iMac at this link: http://www.youtube.com/watch?v=cW8Czra3SBA

Wear-leveling techniques, of which 'Trim' is one iteration, can greatly prolong the life of Solid State Memory. A simplified explanation of how wear-leveling works is that Data is written in 'blocks'; by identifying blocks that can be erased and thus re-used, the SSD controller can spread out usage of all available blocks, so as to prevent over usage of some, and very little, or no use of other 'blocks', thereby evening out the wear of all blocks, and preventing premature failure of the SSD, due to heavy over-usage of as little as even a few blocks.

Lord Xeb said:

MOST of the time, you can expect to get abotu 2-3 years out of an SSD, sometimes longer depending on how much use it gets.

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Mmmm... So if you have a MBA, you are likely to have problems with your ssd by the time Applecare ends. In that not-so-unlikely case you'll have to spend a bunch of money having it changed! Good to know now that I am expecting mine to arrive.

Lord Xeb said:

Now, I can tell you this, out of ALL the MBA I have seen as a mac tech at my local AASP (about a year and 3 months now and we get about 400 apple machines a month), I can tell you I have only seen 4 MBA with SSDs come in that have failed.... I cannot even think of the number of hard drives I have to replace in that amount of time though. Its in the hundreds.

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I get your point. It would be good to know the total number of HDDs sold,compared to SSDs in order to compare anyway. But at least it seems SSD is reliable enough. Let's see what happens in the 1'5 years to come

I have clear that MBA means portability before anything, so, like anything,it has its weak points.

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macs4nw said:

This is the reason, reading from the SSD, does not significantly affect it's lifespan, just the erase/write cycles, and this fact plus the blazingly fast access times of SSDs are why the latter are such a no-brainer for holding your OS and assorted software and programs.

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I didn't know. Thanks so much for the links and time to reply!

Lord Xeb said:

SSD is gone. SSDs are electrical and are more complex than a hard drive, so there is more to go wrong. They also have wear issues (more you write to them, the faster they wear out). MOST of the time, you can expect to get abotu 2-3 years out of an SSD, sometimes longer depending on how much use it gets.

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2-3 years? That's absurd. Much more.

uh someone else said its actually around 30 years if you write 10 gb EVERY DAY before they go down

here:

Weaselboy said:

Your SSD uses MLC type NAND chips rated for 5,000 write cycles. See info below from this article. Even if you write 10GB of data to the SSD every day, it will last 35 years.

Just use it and enjoy it... no reason to worry about wearing out your SSD.

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bravenewmac said:

uh someone else said its actually around 30 years if you write 10 gb EVERY DAY before they go down

here:

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Pretty impressive. And performance should start to significantly decline giving plenty of warning that the SSD needs to be replaced. Should. But as always, back up, back up, back up

AXs said:

2-3 years? That's absurd. Much more.

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Like I said, it all depends on how much the SSD is used and there are other components that can go wrong as well, not just the flash cells.

bravenewmac said:

uh someone else said its actually around 30 years if you write 10 gb EVERY DAY before they go down

here:

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See above comment. Also, the OS itself is writing to the ssd, not just you. 10GB can easily be exceeded and surpassed. That is the lifetime of the cells on a ssd drive, not the other components on the rest of the ssd drive.

ValSalva said:

Pretty impressive. And performance should start to significantly decline giving plenty of warning that the SSD needs to be replaced. Should. But as always, back up, back up, back up

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No necessarily. If the firmware on an SSD just suddently corrupts or if your SSD has a power fault and scrambles your data. Or if the controller on the SSD silently corrupted data? Or what if a flash cell suddenly just failed without warning? None of those would exhibit any form of slowness.

What hasn't been brought up in this discussion is your SSD's life can also be severely impacted also by how full it is. Which drive is going to wear out faster if both has 2 gb of data written and erased every day? A 128gb with 100gb free or a 128gb with only 3 gb free?

Reason is the more empty your drive is, the more space the SSD controller has to spread the 'wear' around. If you want the max performance & life span of your SSD, depending on the controller (Samsung's seem to need the most - Apple uses a ton of these), is about 10-20% free space.

@Lordxeb

You said "expect 2-3 years and SOMETIMES longer"...

meaning most commonly 2-3 years is normal. Which it is not, as you have been proven wrong.

For it to last 2-3 years, that means writing 100GB everyday for 3 years (based on 30 years lifespan of 10GB a day), Or as you can see from the chart, 70 years for 256gb - which is what I have.

That means I need to write 200GB A DAY, EVERYDAY- to have it die in 3 years.

Sure there can be mishaps here and there, which are RARE cases... not normal.

I don't think you should scare people into being cautious with what they write and how much they write.
The Haswell Air's SSD is the best storage tech in consumer electronics right now.

Lord Xeb said:

Like I said, it all depends on how much the SSD is used and there are other components that can go wrong as well, not just the flash cells.

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Just give up trying to spin your wrong answer. SSDs last much longer than your incorrect 2 - 3 years guess.

kodeman53 said:

Just give up trying to spin your wrong answer. SSDs last much longer than your incorrect 2 - 3 years guess.

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Just going off what I have seen. Yes, SSDs CAN last much longer than hard drives, but it all dependent any many factors. Plus, SSDs that have been affordable have not really been all that long in the first place so it is hard to tell exactly how long they will last.

My safe assumption is what I stated before. Am I low balling? Possibly. Can they last longer? Yes. Will they? Who knows as they have not been out long enough to full test. There are simply too many variables. Arguments are pointless on the internet.

Lord Xeb said:

Arguments are pointless on the internet.

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Particularly when you're on the losing end of one. Better luck next time.

It's not even an argument really.

It's like if i said the 13" Haswell Air battery lasts for just 4 hours on light work... it's an inaccurate fact... like claiming that a state of the art SSD will last only 2-3 years.

I could see a case where one could argue 10 years of realistic usage as a primary downloading hub... but 2-3 years is so far off that it can't be true in ANY case.

Well, of course unless someone is seriously writing 100GB a day on 128gb SSD... which is impossible in itself considering size vs capacity.

AXs said:

It's not even an argument really.

It's like if i said the 13" Haswell Air battery lasts for just 4 hours on light work... it's an inaccurate fact... like claiming that a state of the art SSD will last only 2-3 years.

I could see a case where one could argue 10 years of realistic usage as a primary downloading hub... but 2-3 years is so far off that it can't be true in ANY case.

Well, of course unless someone is seriously writing 100GB a day on 128gb SSD... which is impossible in itself considering size vs capacity.

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The reason why I stated 2-3 years is based on what I have experienced and I heavily use my drives... a lot.

The average lifespan of a hard drive is usually between 3-5 years. With solid states, I would say they should be closer to that, but regardless, they have not been out long enough to truly gauge just how long they will last.

Also, kobe, I would love to see you prove to me that I am at the loosing end of this argument. Supply any valid, concrete evidence and I will denounce my statement. Statistics of what things should be on paper are one thing, real-world is another.

Actually, while certain people are playing Who Can Impress Who More With their SSD Scare-Mongering, an important point was completely overlooked:

Ironduke said:

I left the system reinstalling and i got an error, now i go back into dikutil and all it shows is. 1gb partition i can not change this and when i try to install osx again there s no partition to install to

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Ironduke can boot into the recovery partition (NOT internet recovery mode), run Disk Utility, and see a 1GB partition there (which is the recovery partition). This means the SSD is actually still functioning in some capacity.

It's possible that that this Mac COULD be revived if the SSD is repartitioned. If there's a bad block, the repartitioning should hopefully map out the bad parts and swap in some of the overprovisioned space.

Ironduke, if you don't know how to do this, then I would suggest booting your MacBook Air in Internet Recovery mode (hold down Command + Option +R while booting), and let that mode repartition and re-install OS X. With any luck, it should come back in decent shape after this.