In ATTO Disk Benchmark I tried out Queque Depth (QD)=4 and =10. On my recently purchased Win7 notebook there was no difference in the performance test between QD=4 and =10. However, on my 8 year old WinXP notebook, the difference in the performance test between QD=4 and =10 is clearly visible in the output graph. I am not sure what the exact relation is between QD in ATTO, and NCQ. Furthermore, my HDDs have an NCQ depth of 32, while QD in ATTO goes only to a maximum of 10. On my Win7 notebook, I also don't see the relevance of NCQ or QD if large chunks of data (from sector X to sector Y) from the HDD are being dumped into the RAM-DMA during the performance test with ATTO; there is no need for complicated searching on the HDDs where the read/write heads need to wobble over the platters.
Well, the performance of the HDDs (internal and external) on my Win7 notebook is what it is, there is no way to go beyond it physical limits. To me, the most important is that I can get the maximum out of the HDDs and also understand why and how particular parameters in the hardware (HDDs) related to the performance (optimization).
By the way, some time ago we had discussion about misaligned partitions in advanced format HDDs (4K sector drives), like my 2TB exteranl USB3.0 drive. I now performed an ATTO Disk Benchmark test on a partition (on the 2TB HDD) which was first correctly partition-aligned after being created under Win7, and did the ATTO test again after the partition was deleted and re-created under WinXP (so misaligned). The WinXP-created partition had a slightly lower read performance (1% less, not even that maybe) compared to the Win7-created partition. However, the write performance for the WinXP-created partition was something like 10% less than for the Win7-created partition. I get the impression that partition-misalignment may not be that much of an performance issue in advanced format drives. All performance test (including for the WinXP-created partition) where done on the Win7 notebook.
In the process of doing those test, I ran into trouble with my 2TB HDD, which is also my data backup drive. The first partition is a primary partition, followed by an extended partition containing 4 logical partitions; all partition were created under Win7. Then, on my WinXP notebook, after having deleted and re-created the first (primary) partition, the second, third and fourth logical partitions disappeared; the first logical partition, however, and the extended (shell) partition remained intact (checked that out with PTEdit32 and PartInNT). I tried to retrieve the data from the lost partitions using GPartED but after almost 10 hours of "retrieving", GPartED gave up. So, all my data on those 3 logical partitions is gone. Lesson to be learned: WinXP and Win7 are not quite compatible when it comes to partitioning (which I already knew) and that can have disastrous consequences (that I have now learned the hard way).