Comparison Seagate BarraCuda Compute ST3000DM007 3 TB

256/5400

vs Seagate BarraCuda Pro Compute 2.5" ST1000LM049 1 TB

The capacity of a hard disk drive shows how much data the HDD can store—from documents and photos to games, movies, backups, and large work archives. This parameter determines whether the drive is suitable for a simple home system, file storage, or, for example, for long-term accumulation of video recordings from surveillance cameras.

Models small by modern standards are more often chosen for documents, music, and basic files, whereas drives of 4 – 8 TB and larger are already interesting for large media libraries, backups, and NAS systems. Compared to SSDs, high-capacity HDDs are usually more cost-effective per gigabyte, so they are often chosen particularly when the maximum space is more important than record-breaking speed. For example, a drive of 1 or 2 TB might be enough for a regular PC, while 6 – 10 TB could be suitable for a movie collection, family archive, or constant video recording.

The form factor in which the hard drive is made.

This indicator determines primarily the size of the device. But its more specific meaning depends on the execution (see the relevant paragraph). So, in the case of external drives, only the overall dimensions of the case depend on the form factor, and then quite approximately. But internal HDDs are installed in slots with a well-defined size and location of holes for fasteners; these holes are made specifically for one form factor or another. For desktop PCs, the standard form factor is 3.5", for laptops — 2.5" ; at the same time, there has been a recent trend in desktops towards miniaturization and the transition to 2.5-inch drives. Theoretically, there is an even smaller form factor — 1.8", but in fact it is used mainly among ultra-compact external HDDs.

Manufacturer's warranty provided for this model.

In fact, this is the minimum service life promised by the manufacturer, subject to the rules of operation. Most often, the actual service life of the device is much longer than the guaranteed one.

The amount of internal hard drive memory. This memory is an intermediate link between the high-speed computer RAM and the relatively slow mechanics responsible for reading and writing information on disk platters. In particular, the buffer is used to store the most frequently requested data from the disk — thus, the access time to them is reduced.
Technically, the size of the buffer affects the speed of the hard drive — the larger the buffer, the faster the drive. However, this influence is rather insignificant, and at the level of human perception, a significant difference in performance is noticeable only when the buffer size of the two drives differs many times — for example, 8 MB and 64 MB.

— CMR(Conventional Magnetic Recording) is a classic method of magnetic recording, characterized by high data access speed. CMR hard drives are used in systems where it is important to provide high (as far as possible) data read/write speed. These are user computers, security video surveillance systems, etc. The main disadvantage of CMR hard drives is the high complexity of creating volume drives, which is reflected in their price. Additionally, HDDs with CMR technology are quite “gluttonous” in terms of power supply.

— SMR(Shingled Magnetic Recording) — a promising technology for magnetic recording, which is called "tiled". SMR allows to achieve high data density, which in turn increases the capacity of memory drives and lowers their market value. SMR hard drives have slow rewriting speed, which makes such memory drives poorly suited for use in client computer systems. But they have proven themselves well when working as part of data processing centers, archives and similar systems for which low write / rewrite speed is not critical. However, some companies still produce SMR solutions for personal and even mobile systems. These HDDs use an optimized write/rewrite technology called Drive-Managed SMR (DM-SMR).

For drives used in a PC (see "Intended use"), 5400 rpm(normal) and 7200 rpm(high) are considered standard speeds. There are also more specific options, including models with the ability to adjust the speed depending on the load. In server HDDs, in turn, higher speeds can be used — 10,000 rpm and even 15,000 rpm.

The speed of data transfer between the disk and client devices is determined by the type of drive, spindle speed, memory buffer size and connection connectors. The last parameter is the most important, since it is impossible to exceed the bandwidth of a particular interface.

The number of platters provided in the design of the hard drive.

Physically, a hard disk consists of one or more platters, on which information is recorded. Several plates can be provided in order to achieve the desired volume without increasing the form factor. At the same time, it is also necessary to install an appropriate number of reading heads in such a drive, which complicates the design, reduces its reliability, and increases the cost. Therefore, manufacturers choose the number of plates based on a reasonable compromise between these points, and for selection, this parameter is more of a reference than practically significant.

The time it takes for the hard disk mechanics to find random requested data to read. For each specific case, the search time is different, as it depends on the location of the data on the surface of the disk and the position of the read head, therefore, the average value is indicated in the characteristics of hard drives. The lower the average seek time, the faster the disk works, all other things being equal.