SSD Life Expectancy

[Music] welcome once again to explaining computers dot-com in many previous videos I've looked at these things SSDs including installing an SSD is a replacement for a hard drive in a desktop computer or a laptop computer more recently I've looked at the m2 SSDs that plug directly into some modern motherboards now there is no doubt at all that SSDs are faster and more physically robust than traditional spinning hard drives however I do know that many people worry greatly about the life expectancy of an SSD should we really trust our data to a device like this and so in this video I'm going to address SSD life expectancy head-on today almost all SSDs stored data in NAND flash memory cells in case you're wondering NAND is not an acronym but refers to a logic circuit called or not and gate meanwhile flash is a form of computer memory that retains its contents when power is removed however the key limitation of flash memory is that its cells can only be programmed and raised a limited number of times depending on the SSD and its specific technology the maximum number program erase or p/e cycles can be as low as 500 and as high as 100,000 all early SSDs were based on SLC or single-level cell technology this stored one bit of information per cell with modern SLC SSDs rated between 50,000 and 100,000 PE cycles however SLC is very expensive and today SLC SSDs are only manufactured for use in servers and other enterprise applications following SLC came multi-level cell or mlc which stores two bits of data per NAND flash cell storing more data per cell decreases the cost of an SSD but also decreases its writing speed and makes it wear out more rapidly today and I'll see drives come in two variants enterprise or EML C as well as end-user NLC drives the difference between EML C and n LC drives is not that significant saves that the enterprise drives have a lower write speed which is gentler on the cells so causing them to last longer today EML C SSDs are typically rated at between 10,000 and 30,000 PE cycles while end-user mlc drives are typically rated at between 3,000 and 10,000 cycles after mlc we got TLC or triple level cell which stores three bits of data per cell while this further lowers SSD price per bit it again does so at the cost of cell endurance with TLC SSDs having typical PU ratings of somewhere between five hundred and two thousand cycles in case you're wondering quad level cell or qlc SSDs are expected on the market fairly soon in recent years we've also seen the launch of new technologies including Sweden and and vertical land or v-nand SSDs these stack nano flash seldom would ship in order to improve capacity and in the process increase the number of potential p/e cycles however it's important to appreciate that 3d NAND and v-nand are complementary technology developments as Tweedy NAND and veal and SSDs are still produced in either SLC mlc or TLC variants note that the PA cycle figures presented earlier in this video took account of a latest mlc and TLC Sweden and and V none drives all modern SSDs use a process called wear leveling to even out the p/e cycles inflicted on each memory cell across the drive this is particularly important because flash memory cells have to be raised in blocks which means that data has to be constantly moved around an SSD into free space SSDs inevitably wear out faster the less free space they have available imagine for example a 120 gigabyte SSD which is 90% full and has a rating of 1000 PE cycles manufacturers typically work on the assumption of end-users writing up to 20 gigabytes of data in a day and so here if this quantity of data was written and who raised from the 12 gigabytes of free space every 24 hours itself would hit 1,000 PE cycles in just 600 days but if the drive were only 80% full it would last for 1200 days and so on a key takeaway here is that it's good practice to leave adequate free space on an SSD to preserve its life expectancy keeping such free space available is known as over provisioning and some SSDs achieve it internally by including additional memory cells that cannot be accessed by the user meanwhile other SSDs are supplied with software but allows the user to implement over provisioning by leaving some space on the drive on formatted for example Samsung's Magicians software leaves about 10% of an SSDs capacity on allocated in order to increase the life expectancy of the drive to allow users to gauge probable life expectancy SSD manufacturers provide a rating that indicates the minimum quantity of data that can be written before the drive fails the enterprise SSDs and as shown here for some Sun disk drives such ratings may be expressed as a minimum number of petabytes written or PBW with a petabyte being 1,024 terabytes alternatively enterprise SSDs can have their endurance expressed in drive writes per day or DWP D which is a measure of how many times a drive can be filled to full capacity and erased for every day of its warranty period for end-user SSDs endurance ratings are typically expressed in terabytes written or tbw here mlc SSDs typically achieve higher ratings and TLC hardware for the same capacity of drive although Intel's latest 3d TLC technology does book that trend as we would expect we also see that the large of a drive the great of a tbw figure if you are worried about maximizing SSD life expectancy you should therefore purchase the largest drive you can afford and leave it with as much free space as possible this said given that most modern SSDs are able to withstand a good 100 terabytes written or more it's safe to presume that any modern drive in a reasonable usage scenario will last for a great many years and for at least as long as the other components in their typical and use of PC SSDs are getting better and better indeed only a few days ago Intel launched the first drive based on its new 3d xpoint technology rather than traditional NAND flash memory cells as such innovation - crew SSD life expectancy will also continue to improve this said my final message to you on the subject of SSD life expectancy has to be don't panic now absolutely the flash memory cells used in all and user SSDs can sustain no more about 10,000 program erase PE cycles and in many consumer drives that's down to maybe only a few thousand PA cycles and that can sound at first sort of instant rather alarming but as we've also seen in this video most consumer most client SSDs can still sustain at least a hundred terabytes written before they fail and that means for most users in most situations your SSD will last many years and potentially over a decade so should we trust our data - SSDs today well in my view yes absolutely if with the normal provider you should never trust any data to one single drive any data you actually care about you want to be there when you come back again should always be stored on at least two drives and ideally at least three but now that's it for another video if you enjoyed what you see near professor like button if you haven't subscribed please subscribe and I hope to talk to you again very soon [Music]

Channel: ExplainingComputers

Views: 2,987,292

Rating: 4.8910284 out of 5

Keywords: SSD, life, expectancy, endurance, solid, state, drive, program, erase, cycles, P/E, TBW, terabytes, written, PBW, petabytes, DWPD, SLC, MLC, TLC, eMLC, V-NAND, 3D NAND, 3D XPoint, Intel, Samsung, Christopher, Barnatt, wear levelling, wear leveling, over, provisioning, NAND, flash, memory

Id: -XZNr7mS0iw

Length: 9min 24sec (564 seconds)

Published: Sun Mar 26 2017

Reddit Comments

[u/RedSnt]

At first I didn't expect to learn anything interesting from this, but around the 4m34s mark it's revealed that the amount of free space has some significance on the tear of your SSD. I'm sure I'm not the only one struggling with space for games etc. on my SSD, so just wanted to make a note of it.

So the tip is to leave 10% free space.