Some application assumptions feeding into this discussion:
- most data are written once
- read dominated workload (writes may be less than 10% or even less than 1%)
- while there is no locality,
- Why not use flash instead of RAM as the main storage mechanism?
- What is flash latency?
- SSDs:
- Current claims for x25-E: 75 µs read, 85 µs write
- Typical ONFI:
- Micron MT29H8G08ACAH1, 8, 16, 32 Gb
- Read 30 µs, Write 160 µs, Erase 3 ms
- Micron MT29H8G08ACAH1, 8, 16, 32 Gb
- SSDs:
- Can it be made a low enough so it doesn't impact RPC latency?
- What is the latency of typical flash packaging today? 100 µs?
- What is flash latency?
- Does flash offer advantages over disk as the backup mechanism?