Hello, I have LSI RAID card with 2 RADI0 SSD drives sd0 at scsibus0 target 0 lun 0: <LSI, MR9260-8i, 2.13> disk fixed sd0: fabricating a geometry sd0: 952 GB, 975744 cyl, 64 head, 32 sec, 512 bytes/sect x 1998323712 sectors
Reading from the virtual RAID drive gives throughput of 892MB/sec for raw device, but only 53MB/sec for block device. This is NetBSD-8 localhost# dd if=/dev/rsd0d of=/dev/null bs=1m count=10000 10000+0 records in 10000+0 records out 10485760000 bytes transferred in 11.749 secs (892481062 bytes/sec) localhost# dd if=/dev/sd0d of=/dev/null bs=1m count=10000 10000+0 records in 10000+0 records out 10485760000 bytes transferred in 196.552 secs (53348528 bytes/sec) Any ideas why block device I/O is so abysmal? Is this something specific to NetBSD?
