SSD Experiments

Intro

We're looking at SSDs for a few reasons

1. They can provide roughly 2-2.5x the read bandwidth (and sometimes nearly that much for writes, too) of disks.
2. They have much lower write latency (RAMCloud may be attractive without battery backups/Agigatech stuff/etc, if we use synchronous flash writes to get durability.
3. We don't need huge capacity, so the cost is reasonable (~$1.6/GB)

Controllers

There appear to be half a dozen different manufacturers of SSD controllers (Marvell, Intel, JMicron, Samsung, Indilinx, Toshiba, Sandforce).

Troublingly, some controllers or associated firmwares appear to be considerably less reliable than others (judging from consumer reviews on, e.g., NewEgg.com). E.g. the Indilinx and JMicron ones seem especially suspect. Sandforce-based drives also look a little sketchy depending on the vendor (perhaps they're making stupid firmware modifications?). Even Intel appears to ship buggy firmware!

Evaluation

We looked at 4 drives with chips from Marvell, Intel, Samsung, and Toshiba:

Write Performance