Now we can move on to performance characteristics. We see that the average access time of the Samsung drives is worse than that of Hitachi’s products (Hitachi inherited high-performance mechanics from IBM) and Seagate’s (this is only true about SATA models from Seagate, see this article for details). Yet, Samsung surpasses all its rivals in the track-to-track seek time, and this parameter has a greater impact on the performance than the average access time, since there’s a high locality of data on the disks of a home computer and “far seek” occurs less often than track-to-track movements of the heads.

The data density parameters are average with Samsung. Maxtor, on the one hand, went for an extreme, increasing the bit density, while Seagate, on the contrary, improves the track density. Samsung’s characteristics are more balanced, but we shouldn’t forget about the above-mentioned technology for choosing an individual density for each head/surface pair, making such comparisons incorrect. Our experiments suggest that the SpinPoint P80 series, like Maxtor’s DiamondMax Plus 8/9, can include models on 80GB as well as 60GB platters. Thus, the skipped-over SpinPoint P60 series is now “combined” with the P80. When the 80GB platter is redundant – for 60GB and 120GB models – they just use a lesser-density platter of 60GB capacity.

I’d like to offer you the zone maps of several samples of SpinPoint P80 family drives, given to me by Mikhail Mavritsin a.k.a. hwdiver. For better readability I represent them as graphs for each surface independently. Each of the tested drives had 24 density zones, but the zones themselves vary considerably.

This sample has a lesser track density on the first surface than on the second one, while the number of the tracks is identical. Thus, the capacity of one surface is a little below 40GB and of the other – a little more. The two give us the required 80GB in total. Comparing the total number of sectors on the zone map with the number reported by the HDD itself, we learn that about half a percent of capacity vanished somewhere. These sectors must have been left as a reserve for replacing defective sectors.

The different surfaces of this sample of the SP1203N have practically the same sector density, but the required capacity of 120GB had to be accumulated in some other way. The second surface has the same number of tracks as the previous tested sample; the first surface has fewer tracks (but the sector density is maximal); the third surface has more tracks.

We see some original combinations more in this biggest-capacity model. Two surfaces have an absolutely identical format, exactly coinciding with the format of the second surface of the previous sample. One more surface has a slightly lower sector density, and third has record-breaking sector and track densities!

Overall, you have seen three variants of the possible amount of tracks (80033, 83153, and 86448) in three samples of the SpinPoint P80, and numerous variants of the sector density, among which we can single out the most common one. Thus, Samsung does use adaptive formatting in the latest generation of its hard disk drives. With this technology, each density zone may vary in the number of sectors as well as tracks, maximizing the use of the platter surface without compromising data reliability. Some discernable regularity makes us think that Samsung uses different track densities (in tracks per inch – TPI) for each surface, but we haven’t yet received an official confirmation or denial of this hypothesis.

Lastly, I’d like to dwell on another HDD characteristic, which is directly linked to reliability but is often left in the background – ECC.