jerf, the oddest part is that if you read through the de-duplication and redundancy designs of modern SSD controllers (like the SandForce SF-2k series) not only do the drives do automatic de-duplication and compression on the fly, the scatter the bits evenly across the memory arrays (in parallel) to control even wear-and-tear of R/W cycles on the memory.
Then they typically write the bits to multiple locations or an entire section of the drive is maintained for parity information, sort of like an on-disk RAID5 setup where the individual blocks of NAND can be though of as "disks". For example, a 120GB drive typically has something like 150-160GB of storage space on the disk. This is not unlike what spindle disks do with a large section of disk not allocated to the format operation and kept behind for failed sectors that are re-allocated by the controller.
So all that work and the failure rates are still too high for comfort. It's really surprising to me and suggests that all of this needs more baking time.
I have no idea what the failure rates are in lower-end drives like the Kingstons and other drives that are likely rebranded garbage. I imagine it's not any better :)
the interesting this is that Macbook Air are all SSDs - so unless OSX is doing something terribly creative, why arent we seeing the same kind of return/failure rates on Macbook Airs ?
There's a tradeoff between speed and reliability, and the Samsung SSDs that I believe are used in the Macbook Airs lean towards reliabilty at the expense of having non-random IO no better than a normal hard drive. People who buy SSDs by themselves, on the other hand, are often just going down a list of offerings comparing IO speed to price and not having any good way to look at the reliability.
Then they typically write the bits to multiple locations or an entire section of the drive is maintained for parity information, sort of like an on-disk RAID5 setup where the individual blocks of NAND can be though of as "disks". For example, a 120GB drive typically has something like 150-160GB of storage space on the disk. This is not unlike what spindle disks do with a large section of disk not allocated to the format operation and kept behind for failed sectors that are re-allocated by the controller.
So all that work and the failure rates are still too high for comfort. It's really surprising to me and suggests that all of this needs more baking time.
I have no idea what the failure rates are in lower-end drives like the Kingstons and other drives that are likely rebranded garbage. I imagine it's not any better :)