Two things that everyone needs to know about SSD's:

They have a limited number of write sequences which varies by 
manufacturer and the way that reported number (of write sequences) is 
derived, varies by manufacturer as well. This is probably a non-issue 
for us mere mortals because we will probably never reach the limit of 
write sequences for a given SSD. It is something to consider for those 
considering a server based system. SSD's are now being used in servers 
and the accumulated data is around the corner. Backblaze is a good 
source of data for drives used in a server base system.

What happens when an SSD reaches its write sequence limit? It simply 
becomes a read only device so the data isn't lost. All SSD's that I know 
of have built in software to warn the user when the number of writes is 
about to hit the wall.

One thing that can happen to an SSD (and occasionally does) is 
catastrophic failure. When that happens, the data is un-recoverable. 
Unlike a spinning platter drive where the data can be recovered if it is 
important enough to spend the money with a recovery company.

So, to paraphrase the IT professionals: "You are only as good as your 
last backup".

Cheers!

Corey
Corey Bailey Audio Engineering
www.baileyzone.net


On 1/13/2016 12:40 PM, Arthur Gaer wrote:
> I'm unaware of any issues with X-ray systems and SSDs.  Given the large number of people who are putting their SSD equipped laptops through airport X-Rays I think one would have heard long ago if there were any significant data loss concerns.
>
> The last time I saw any numbers--and these are all manufacturers estimates from a couple of years ago, so take it with a huge amount of salt--SSD's were said to have a Mean Time Between Failure of about 2,000,000 hours vs 1,500,000 for traditional hard disk drives.  Your mileage might vary wildly.
>
> Actually failure/replacement rates are highly proprietary for any of those vendors.  You'd need to be the NSA to get at that data.   Or a company as big as Apple who's deployed hundreds of millions of those drives and have their own internal statistics.
>
> Arthur Gaer
> [log in to unmask]
>
> Senior Systems Manager
> Harvard University
> Department of Mathematics
> Science Center
> 1 Oxford Street
> Cambridge, MA 02138
> 617-495-1610
>
>
> On Jan 13, 2016, at 2:35 PM, CJB<[log in to unmask]>  wrote:
>
>    
>> Thanks folks for your opinions and expertise. What's the risk of
>> losing all data stored in a SSD going through an airport x-ray machine
>> or worse? And what's the expected longevity (i.e. of the integrity of
>> data recorded) compared to a high end spinning mag. drive? Let's say
>> at the Terabyte level of storage. Thanks - Chris B.
>>
>> On 13/01/2016, Arthur Gaer<[log in to unmask]>  wrote:
>>      
>>> Mac laptops can only be configured with Solid State Drives now.  They
>>> haven't put spinning hard drives in laptops for several years, though you
>>> can get the SSD's up to 1terabyte in size.
>>>
>>> The one exception you shouldn't waste money on: it's a single low end model
>>> that hasn't changed since 2012, heavy, with a slow processor and slow
>>> memory, low res screen, etc.  It's not a modern computer.  Even Apple's
>>> cheaper laptops take SSD's.
>>>
>>> The fact that Apple, which has to service their own systems, has gone to all
>>> SSD's should tell you a lot.  SSDs have no moving parts so less prone to
>>> failure, especially in a laptop environment where they're subject to all
>>> sorts of physical stresses.  They're also roughly 5-10X faster than a
>>> spinning hard drive, use far less energy (which increases battery life in a
>>> laptop) and put off far less heat (which means less cooling and thus greater
>>> battery life in a laptop).  They also don't add vibrations and they take up
>>> a lot less space in the confines of a small laptop.
>>>
>>> SSD's keep getting faster and even more reliable while the prices keep
>>> dropping precipitously.  There's only three hard drive manufacturers left in
>>> the world.  I'd be shocked if there were still production lines in 10 years.
>>>   I wouldn't be at all surprised to find them gone in five years.
>>>
>>> Arthur Gaer
>>> [log in to unmask]
>>>
>>> Senior Systems Manager
>>> Harvard University
>>> Department of Mathematics
>>> Science Center
>>> 1 Oxford Street
>>> Cambridge, MA 02138
>>>
>>>
>>>
>>>
>>> On Jan 13, 2016, at 1:38 PM, Adam Jazairi<[log in to unmask]>  wrote:
>>>
>>>        
>>>> The technology is similar (both are non-volatile solid-state memory), but
>>>> the flash drives you'll find on a laptop nowadays generally have more
>>>> storage than an SD card and are much faster. That said, a 1TB SSD will
>>>> cost
>>>> a premium compared to a 1TB HDD. It's been a couple years since I bought
>>>> my
>>>> Macbook Pro, but I think it was something like $200 extra just to upgrade
>>>> from 128GB to 256GB.
>>>>
>>>> On Wed, Jan 13, 2016 at 1:07 PM, CJB<[log in to unmask]>  wrote:
>>>>
>>>>          
>>>>> Thank you - but aren't flash drives the same as SD cards?
>>>>>
>>>>> But a 1TB conventional drive seems OK.
>>>>>
>>>>> CJB
>>>>>
>>>>> On 13/01/2016, Stewart Gooderman<[log in to unmask]>  wrote:
>>>>>            
>>>>>> MacBook Pro 13” can be gotten with a 1 TB hard drive.
>>>>>> MacBook Pro 15” can be gotten with a 1TB flash drive.
>>>>>>
>>>>>> DrG
>>>>>>
>>>>>>              
>>>>>>> On Jan 13, 2016, at 9:14 AM, CJB<[log in to unmask]>  wrote:
>>>>>>>
>>>>>>> BTW if anyone knows of a brand (not Lenova with in built spyware) that
>>>>>>> offers laptops with proper hard-drives do let me know. As others have
>>>>>>> opined re: SD cards aka solid state 'drives' of limited robistness,
>>>>>>> please let me know.
>>>>>>>
>>>>>>> CJB.
>>>>>>>
>>>>>>>                
>>>>>>              
>>>>>            
>>>>
>>>>
>>>> --
>>>> Adam Jazairi
>>>> Digital Collections&  Preservation Librarian
>>>> Boston College University Libraries
>>>> (617) 552-1404
>>>> [log in to unmask]
>>>>          
>>>        
>