> I was wondering if anyone had a benchmarking showing this alignment > mattered on the latest SSDs. My guess is no, but I have no data.
I don't believe there can be any doubt whether a Flash based SSD (tier1 or not) is negatively affected by partition misalignment. It is intrinsic to the required asymmetric erase/program dual operation and the resultant RMW penalty to perform a write if unaligned. This is detailed in the following vendor benchmarking guidelines (SF-1500 controller): http://www.smartm.com/files/salesLiterature/storage/AN001_Benchmark_XceedIOPSSATA_Apr2010_.pdf Highlight from link - "Proper partition alignment is one of the most critical attributes that can greatly boost the I/O performance of an SSD due to reduced read modify‐write operations." It should be noted, the above highlight only applies to Flash based SSD as an NVRAM based SSD does *not* suffer the same fate, as its performance is not bound by or vary with partition (mis)alignment. Best regards, Christopher George Founder/CTO www.ddrdrive.com -- This message posted from opensolaris.org _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
