Erase Block (Alignment) Misinformation?

[Quad5Ny]

Does it really matter if partitions are start/end on a Erase block?

There are tons of threads and articles online saying you should align your partitions to start on a erase block. For the life of me I can't see why that would be relevant because the OS doesn't actually ever erase anything it only Reads/Writes.

Erasing of old data should be taken care of by the SSD's controller. So as long as your writes are aligned to the page size of your drive, everything should be just fine... shouldn't it?


P.S. I just purchased 4 Samsung 830 Series SSD's to put in a few Mac's, does Lion/Mountain Lion align the partitions correctly for the 830's? (I can't seem to find the page size Samsung's Toggle-mode DDR NAND.)

 

[hhhd1]

SSDs do not work like old HDDs, it can not do overwrite, when you try to overwrite something, the SSD actually first must erase the block, and then write to it ONLY when it is empty.

 

[Quad5Ny]

Yes, I know but the OS itself never actually erases anything (not counting Trim commands).

AFAIK the the controller on the drive should be choosing what data should be erased (or Read-Modify-Erase-Write) not the operating system. Which was why I was asking why everyone seems to want to align partitions to Blocks, not Pages.