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Flash has certain disadvantages that favor using a controller instead of direct addressing like DRAM. To make SSDs fast, you have to do wear leveling, command q
by AngryParsley 16y ago
Flash has certain disadvantages that favor using a controller instead of direct addressing like DRAM. To make SSDs fast, you have to do wear leveling, command queueing, and parallelization of requests across all flash chips. Oh and when a cell fails, you have to remap spare cells. Doing this stuff in software would be a giant pain.
You can get raw flash chips, but it's hard to get decent performance and reliability out of them. That sort of setup is usually for embedded systems where writing is rare and read performance isn't important. Firmwares for switches and routers, for example.
- Hoff 16y agoWhile I understand your comments and that this can get hairy, also consider a softmodem-like implementation as a counter-example. A softmodem (variously also called a Winmodem) is a partial or full software implementation of a modem, and helped reduce the parts counts and the costs of modems. Ugly or not, it's a near certainty that we'll see a software (or firmware) implementation of this; some sort of "softssd" or "winssd" scheme.
- deleted 16y ago[deleted]