Fancy trying if it would behave differently with the NCQ branch? Jaromir
2017-07-03 6:34 GMT+02:00 Thor Lancelot Simon <t...@panix.com>: > > On Sun, Jul 02, 2017 at 10:57:20PM +0100, Patrick Welche wrote: > > On Fri, Jun 30, 2017 at 12:00:45PM -0400, Thor Lancelot Simon wrote: > > > > I shoved a rather newer ST2000DM001-1CH164 in, which according to its > > marketing bumpf can manage "Max SustainableTransfer Rate 210MB/s" > > and not so bad: > > > > # dd if=/dev/zero ibs=64k | progress -l 976751887b dd of=/dev/rdk15 obs=64 > > k > > 99% |********************************** | 465 GiB 116.74 MiB/s 00:00 ETAd > > This is already effectively double buffered, because of the way you used > "progress". You could try using a larger blocksize for the reads from > /dev/zero (1m perhaps) and also for the writes to rdk15 - the kernel > will buffer up and dispatch the MAXPHYS sized I/Os. > > To get 200MB out of that drive you likely need larger writes, which we > currently can't do. It might perform slightly better through the > filesystem, though. > > Thor