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Comparison WD Purple Surveillance WD42PURZ 4 TB
42PURZ
vs WD NasWare Red WD40EFAX 4 TB
SMR

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WD Purple Surveillance WD42PURZ 4 TB 42PURZ
WD NasWare Red WD40EFAX 4 TB SMR
WD Purple Surveillance WD42PURZ 4 TB
42PURZ
WD NasWare Red WD40EFAX 4 TB
SMR
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from $129.99 
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Placementbuilt-inbuilt-in
TypeHDDHDD
FeaturespCserver
Size4000 GB4000 GB
Form factor3.5 "3.5 "
ConnectionSATA3SATA3
Manufacturer's warranty3 years5 years
Technical specs
Cache memory256 MB256 MB
Record technologyCMRSMR
RPM5400 rpm5400 rpm
Data transfer rate175 MB/s180 MB/s
MTBF1 M h
MTBF300 K
General
Size147x102x26 mm147x102x26 mm
Weight570 g
Added to E-Catalogmay 2022march 2020

Features

The general purpose of a hard drive is the type of devices for which it was originally intended.

For PC. Hard drives designed for use with conventional consumer computers and laptops. At the same time, the possibility of installing an internal HDD (see "Performance") directly depends on the form factor (see the relevant paragraph), while external models are not subject to such restrictions — it is enough for them to have the appropriate connection connector. Also note that almost all external hard drives are designed specifically for PCs; making server models external is not technically justified.

For the server. Hard drives designed for servers have increased speed and reliability, because they constantly have to receive and give large amounts of information. To ensure speed, they may provide an increased rotation speed (up to 15,000 rpm). Such drives are made only internal (see "Performance"), and, in addition to SATA, they can use other, more specific connection methods — for example, SAS(see "Connection interfaces").

For game console. Specialized hard drives designed for use with game consoles. They are made only external (see "Performance"), they are intended mainly for storing games — including saves and user settings profiles. The main difference between such devices and classic external HDDs is...precisely the optimization for working with game consoles, including the availability of special software tools for improved integration. Many of these drives are originally designed for a specific model or family of set-top boxes.

Manufacturer's warranty

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.

Record technology

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).

Data transfer rate

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.

MTBF

Guaranteed (minimum) hard drive uptime. The longer the time between failures, the more durable and reliable the device. At the same time, we note that after this time, the drive will not necessarily fail immediately — most models remain operational even after the claimed resource has been exhausted, but the manufacturer does not give any guarantees here.

MTBF

Guaranteed (minimum) number of hard drive on-off cycles after which it will remain operational. The higher this number, the more reliable the drive.
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