alt Hacker NewsWhat SSDs are reasonably performant without a volatile write cache? The standards you quote specify why it is necessary to issue flush!
What SSDs are reasonably performant without a volatile write cache? The standards you quote specify why it is necessary to issue flush!
Per the definition of volatile write cache in the standard I quoted, pretty much any drive TLC drive in the hyperscalar, datacenter, or enterprise product lineup will have great write performance. They have a DRAM cache that is battery-backed, and as such is not a volatile write cache.
A specific somewhat dated example: Samsung 980 Pro (consumer client), PM9A1 (OEM client), and PM9A3 (datacenter) are very similar drives that have the same PCI ID and are all available as M.2. PM9A3 drives have power loss protection and the others don’t. It has very consistent write latency (on the order of 20 - 50 μs when not exceptionally busy) and very consistent throughput (up to 1.5 GB/s) regardless of how full it is. The same cannot be said of the client drives without PLP but with tricks like TurboWrite (aka pseudo-SLC). When more than 30% of the NAND is erased, the client drives can take writes at 5 GB/s but that rate falls off a cliff and gets wobbly when the pseudo-SLC cache fills.