Today a ssd replaces your OS mechanical drive as you can buy a 256gb ssd within reason. What make ssd so good is access time, a mechanical drive takes much longer to access your data, an ssd its pretty much instant.
Buying an SSD is however not so easy though.
There are 3 different flash memory technology that the manufacturer uses.
The two most used are MLC a 2 bit flash and TLC a 3bit flash. The main difference is here, TLC is the cheaper solution. What complicates things are that a flash cell can withstand x number of writes.
40nm flash for example MLC can withstand 10k writes. A 16nm MLC maybe 1k.
When the shrinking of flash happens then we have electron issues that means the flash cell cant hold the charge without having interference from cells close by. The manufacturer then adapt to this with algorithms and controllers that decide how many writes is done and when they get old. Bugs however happens so a firmware needs to be updated.
Recently the Samsung 840 evo had a bug of slow down when old data who just sat there slowed down. Samsung recently sent a restoration tool with new firmware where the tool flashed new firmware and restored the drive. My own crucial M4 I flashed 4 times new firmware into it, never had any issue with the drive but I always flash recent new firmware to make sure it stays updated.
The samsung bug was due to the flash cells changes over time and the firmware didn’t account for that enough. The samsung 840 evo has TLC flash memory cells in it.
Recently Samsung created a new flash a so called 3D they call it V-Nand. It means they stack the cells above one another up to 32 layers currently and then make holes into it. The benefit with this approach is they can use older flash 40/32nm with 32 layers which means they can have a much better endurance with the writes.
SSD is a good thing to have, buying one one need to think before as you don’t want the cheapest one at all times.
One I would upgrade to are the samsung 850 pro due to V-nand but mainly for endurance. I use my drive for OS and games. I need small files to be written more than moving large files. The 850 pro then will make sure my system stays up for a long time and offers me consistency there.
Normally I recommend brands like Intel as those guys often if not always write their own firmware to their drives. Samsung are good also and Crucial.
The main thing about buying an ssd are
What flash type do they use?
MLC or TLC
Then what controller do they use to make it work?
Intel, samsung crucial often have different generation controllers depending what ssd you buy.
What size of flash?
The size matters, the smaller the flash 20nm or 16nm the less writes it can handle while that normally wont matter much as the manufacturers controller and software handles this pretty good nowadays.
For example, the Samsung 840 PRO use MLC that is a bit more expensive than their 840 EVO that use TLC flash. So if one use important work for the drive, school etc..then I rather buy a 840 Pro due to its likely to hold up better even though its highly unlikely that the EVO wont do as good a job as the PRO version.
Many manufacturer just slap their own brand upon a drive that someone else makes. So buying a drive for a normal user then pretty much today any SSD are really good to buy.
Normally an ssd last a long time. My 4 year old crucial m4 128gb still has 95% left on it. The main reason for me to upgrade is size. I have 10gb free so then I am thinking I need more room for what I use the computer for. If the degradation is 5% in 4 years I can still use it, 80! years from now assuming the same use.
My recommendation is the Samsung 850 pro without doubt. Second would be more MLC based drives.
Like: Intel 530 series, crucial m500, M550, MX100, Samsung 840 pro or such. I also recommend a 256gb as minimum. An OS drive benefit a lot from ssd, the better 4k writes and read let you have a better experience with the OS to start and close programs.
I been really happy with my crucial drive and even if the ssd tech is 4 years old it still going strong for me. I haven’t any real need to replace it heh except for size.
256gb seems to me to be the size to go for today.
Even though I can have a 512gb for less than I paid 4 years ago for 128gb. It moves the right way.
More with some pretty pictures also here.
What can be notable is this,
the new 3D V-nand is using older flash at a bigger size to avoid the interference of electrons that disturbs the flash cells when you shrink flash down which will cause degradation if not kept in check. The good thing is Samsung can use bigger and older flash to increase durability and endurance while still allow faster speeds than current shrinking of 2d nand. This technology as far I can tell is awesome.
Importance using an ssd is this,
I quote “ Top 5 Most Frequent Drive Accesses by Type and Percentage:
- -4 Read (8%)
- -4K Write (58%)
- -512b Write (5%)
- -8k Write (6%)
- -32k Read (5%)
Top 5 account for: 80% of total drive access over test period “ end quote
The speed of an ssd is then not about the sequential speed first and foremost like 500mb/s but about those small files your OS like windows 8.1 does when booting up, when you game etc.. The write number is the key here, buying a cheap drive is then likely to not have the best 4k write numbers that is the key criteria I use for a ssd drive. The good thing since the sata interface started to become the limit soon much any ssd will only differentiate between in size.
Buying an ssd, check the 4k write numbers as 10mb difference is a lot here. The 500mb sequential speeds marketing use is secondary when you decide. Samsung 3D nand changes the endurance due to using bigger and older flash, that has better sustained write performances. Older and bigger flash 40nm or 32 down to 25nm is a better option for an ssd drive due to the die shrink for 2d nand 20nm and smaller also starts to cause electrons to interfere with the flash cells more easily.
One reason the samsung 850 pro ssd stands on my buy list as nr1.