Why do larger SSDs last longer than the smaller ones?

[Vlad_911]

I've seen charts showing that and I'd like to know why that is so.

Thx in advance!

 

[geofelt]

Each nand block has a finite number of writes available.
Larger ssd's have more nand blocks so they can tolerate more total writes and last longer.

 

[USAFRet]

I've seen charts showing that and I'd like to know why that is so.

Thx in advance!

Lets look at a physical analogy...a brick patio. All individual blocks. The bricks represent the NAND cells in the SSD.
a 10'x10' patio has...250 bricks (250GB drive). Each brick can be written on with chalk 10 times before it starts to look bad.
Lets write on 100 of those bricks (100GB of data). Erase, write, erase, write.
The drive firmware shuffles those writes around, so that no individual brick gathers too many write/erase cycles.
Wear leveling.

Now...lets take a 10' x 20' patio. 500 bricks (500GB drive).
Again, lets use 100 bricks of data. Again, writing on 100 of them.
The drive firmware has LOTS more empty bricks to shuffle those chalk marks around on, before any individual brick starts to look funky.

This is also why you don't fill an SSD up too much. The firmware has little or no empty space to shuffle things around to. Some of those cells will wear out a LOT faster if you do that. And you can't unfunk a cell. Once its gone, its gone.