![]() That trick is quite good for sustained performance. they swap cylinders and heads, so if you ask it to write a whole cylinder it will use only one head and a lot of cylinders, that way the speed is more or less uniform along all the cylinders, so they 'fake' most tools to benchmark speed (speed seems to be constant all along the disk), what is the real is that the disk is storing what external is asked to be done in one cylinder, in multiply cylinders so the speed is (per external asked cylinder): fast, medium, slow So the question of where to put files is simple, do a zone speed test (read and write), that way you will know where is better to put files.īeware there are new HDDs that use another technique to 'fake' such different speed depending on the cylinder. physical disk could do a 10GiB/s read (from surface to Buffer) and 6GiB/s write (from Buffer to surface). The disk is so fast that a Sata III controller is the one that limits the transfer sustained speed. I own a vry expensive HDD that can move each head to a different cylinder at the same time, so can read at same time from different cylinders, and it uses an internal Buffer not of 8MiB or 16MiB, it uses a full GigaByte Buffer. That is based in the concept that HDD rotates at a constant R.P.M., among not all HDD works like that. Most modern HDD (all that has park heads since i know) use the oposite, the first cylinder is on the outer part, so much more data stored per rotation, so higher speed on outer cylinders. Some HDDs first cylinder si in the inner part, so less data stored per rotation, so lower speed on lower cylinders. ![]()
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