sorry for my noobishness, but from what I've understood, there's three essential statistics about a hard drive:
read & write speed (linear access) , and access time (random access).
Now I might miss other things ...
great ... I've read so many reviews filled with boring statistics...
But not a lot of literature concerning "intended use" (go and figure out yourself).
You forgot the most important thing that determines the "speed" of a hard drive: firmware
The access time and transfer rates show only the physical stats of the drive, but not how well the firmware uses them. If you look at this SR chart , it shows the 15k.4 and 15k.5 . Despite the newer version having faster access, and higher STR, it shows that it is slower then the older version for *single user* benchmarks. So the newer "faster" drive (by specs) is actually slower in real-world usage (for single users of course).
What causes this? The firmware. In fact, SCSI drives are not the fastest anymore for workstations and single users, because their firmware is being optimized for multi-user server usage. That's why the server benchmarks show an increase from the older to newer drive. As a result of that, the single-user scores go down.
But even in regular SATA drives, look at the WD Black 1Tb and the Samsung F1 1tb drives. They have roughly the same specs, and use roughly the same platter densities. It's the drives firmware that really makes the difference in benchmark testing, since their physical specs are all about the same.