Comment Re:What about long-term data integrity? (Score 5, Informative) 438
The problem is the way how flash itself works, and how smart your controller is. Unlike a disk, flash must be erased before writing. And here is where the problem comes: flash data is stored in a page of cells, with typically 8 pages of data per "block". Erasing happens on the block level. So in order to erase a single page of data, you need to erase all 8 pages in a block. Since you need to keep the data of the other 7, you first need to copy that data into another block, erase the original one, write all data back and erase your "tmp" block. The churn on blocks happens a lot faster than what you'd think.
Having that said, for consumer products, MLC or TLC is perfectly fine. For enterprise, not so much.
You'll see that in the price, obviously. TLC is the cheapest, followed by MLC, and the most expensive technology is SLC.