Hello, Mark Lord wrote: >> That's interesting. One important side effect of issuing IDENTIFY is >> that they will serialize command streams as they are not NCQ commands >> and thus could change command patterns significantly. > .. > > SMART is the opcode that is most frequently implicated here, not IDENTIFY. Yeap, any non-NCQ commands would do it. > Note that even a barrier FLUSH CACHE is non NCQ and will serialize > the stream. Yeah, I was just thinking that issuing non-NCQ commands mixed with NCQ commands would make the command stream fluctuate more. Modern drives are pretty good at lowering power consumption while idle so being more fluctuative (is it a word?) might have something to do with the problem. Just a wild speculation tho. Thanks. -- tejun -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html