>>>>> "Ric" == Ric Wheeler <rwheeler@xxxxxxxxxx> writes: Ric> One other thought - is there a way to give non-rotational devices Ric> also some indication of latency? (FLASH is slower than enterprise Ric> SSD is slower than DRAM ramdisk for example)? The current SBC draft only distinguishes between rotating media speeds. There is only one classification for non-rotating media in the block device characteristics VPD. For a mechanical disk drive the rpm isn't a terrible gauge for performance. But for a solid state device I think it will be hard to define a similar universal metric. Ignoring SLC vs. MLC for a moment I think it's also safe to predict that the enterprise drive of today will be the consumer drive of tomorrow. Maybe the ssd device could export the anticipated command response time for a request that matches the Optimal Transfer Length field in the block limits VPD? -- Martin K. Petersen Oracle Linux Engineering -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
