Talk:SATA

Regarding performance: I'm after that since 1.5 years now since I've got a Cubietruck back then: https://groups.google.com/forum/#!topic/cubieboard/tD0AxHx5Ync

I've never seen sequential write speeds exceeding 50 MB/s (all measurements reporting more were based on wrong methods) but read speeds are able to climb above 200 MB/s. SATA performance scales somewhat linearly with both CPU and DRAM clock and also some kernel config settings give an extra 3%-5% performance gain: CONFIG_SCHED_MC=y and CONFIG_SCHED_SMT=y

I will verify these correlations within the next few weeks with 4.0 or 4.1 but would propose that it should read in the meantime: "SATA throughput is unbalanced for unknown reasons: With appropriate cpufreq settings it's possible to get sequential read speeds of +200 MB/s while write speeds retain at approx. 45 MB/s. This might be caused by buggy silicone or driver problems" Tkaiser (talk) 22:59, 21 June 2015 (CEST)


 * Done. One thing that comes to my mind: How does this compare to other ARM-based SATA implementations? (Investigate if this is a more general limitation, or a problem specific to the Allwinner platform.) -- NiteHawk (talk) 13:43, 22 June 2015 (CEST)


 * On i.MX6 one gets roughly 90 MB/s write and +100 MB/s read (without extensive tuning), Marvell's Kirkwood/Armada are known to provide similar or better results. It must be something special to Allwinner A10/A20, maybe a hardware quirk or a few lines of code in Allwinner's ahci driver that have never been touched? I'm too inexperienced at this level to dig deeper. Just have some knowledge/experience testing storage since I'm doing this partially for a living. -- Tkaiser (talk) 14:54, 22 June 2015 (CEST)