I twist and turn, I want to confuse. Understanding HDD lines

Today there are four models on the agenda. The smaller capacity is only 1 TB, which is already a minimum in this class: so much fits on just one platter. But they are very different in characteristics, despite the fact that all four models “belong to the pen” of the same company. Let's get to know them better.

Western Digital Green WD10EZRX

A representative of the “green” series with all that it implies - after Seagate refused to produce low-speed models, these remained only in the WD range and in the form of only two families. Red is a completely different story: they are intended for use in NAS and similar equipment, so even on the company’s website they are listed outside the desktop models section. But Green is included in it, and sometimes they are even the main and only ones in the computer. However, as we already know, this is not entirely correct, since the platter rotation speed reduced to 5400 rpm has a disgusting effect on performance, but many are willing to do this for the sake of silence and low power consumption of such models. Moreover, this time we have a hard drive with a smaller capacity than in the previous article, but it has only one platter with a capacity of 1 TB, which has a positive effect on the characteristics mentioned above and increases performance. So let's see how much, taking this model as the base one.

Western Digital Blue WD10EALX

Although in fact the Green series is not the youngest in the WDC assortment. The Blue line claims this role, which can most accurately be described by a line from an old song: I made him out of what was:) In fact, this is true - in the blue family, for example, there are still models with a PATA interface, and the maximum capacity is only one terabyte. However, in the latest modifications (namely WD10EZEX), this volume is achieved using only one plate, so it differs from WD10EZRX only in the spindle rotation speed. But we took a slightly different model: lower density, but without Advanced Format. And let’s try to see how a double-plate with a higher rotation speed will look against the background of a single-plate with a lower one.

Western Digital Black WD1002FAEX

If in the segment of laptop drives the “blue” and “black” lines differ very clearly in rotation speed, then in the desktop market there is no such thing. Formally, Black is faster, but today it’s difficult to understand why. Except that the cache capacity differed for a long time, but after the introduction of Advanced Format, 64 MB became the standard for everyone. WD1002FAEX, however, does not use it yet. In general, the technical characteristics of the mechanics are identical to the WD10EALX, but it is superior in cache and, possibly, firmware. So let’s compare these two hard drives in practice.

Western Digital VelociRaptor WD1000DHTZ

This drive appeared on the market quietly and unnoticed, which greatly distinguishes it from its predecessors. Although this is not surprising - circumstances have changed.

The highlight of all Western Digital (WD) drives is the free “Acronis True Image WD Edition” program, which allows you to backup your operating system and data. All WD hard drives are divided into series depending on their purpose.

Different series of WD disks have their own characteristics and are designed for different ways of using them, and to distinguish them they came up with color coding, which is quite convenient. The user can only determine the range of tasks for which the disk will be used.

WD Blue

If you use your hard drive to store travel photos, a wedding album, or a collection of your favorite TV series, then WD Blue is exactly what you need. WD Blue drives are designed and tested to suit your needs and come with a 2-year warranty. Enhanced data protection is based on contactless read technology, which ensures the recording head is securely positioned above the drive surface. This is the most popular low-cost series of WD hard drives with a standard spindle speed of 7200 rpm.

W.D. Green

A series of quiet and economical hard drives. They are also low-cost solutions like WD Blue, but have a reduced spindle speed of up to 5400 rpm. This ensures reduced noise and heating levels. Also, hard drives from the green series periodically turn off themselves to reduce power consumption. In general, they are more suitable for file storage that is accessed infrequently. They are not suitable as the main disk for the system or as a second disk for constant work throughout the day, since frequent starts and stops of the disk lead to increased wear.

WD Black

The WD Black line is designed for advanced users and is perfect for photographers, designers and, of course, gamers. Dynamic caching optimally distributes cache memory to achieve maximum performance regardless of disk usage scenario, even in such heavy tasks as video editing and modern cinematic games. High operating speed is also achieved due to the 2-core processor. The WD Black drive keeps your data safe and comes with a 5-year warranty. These drives are fast, reliable and perfect for use as the main or second drive for gaming and professional PCs.

WD Red

For stable operation of a NAS network drive, it is best to use the WD Red line. The scope of their application is very wide - from home storage or small offices to corporate sites. NAS Hard technology reduces power consumption, increases hard drive performance, and is optimized for NAS storage systems. Media in the Red line are designed for 24/7 load and have a 3-year warranty. They also use power-off technology when there is no activity, which is good for file archives in periodically used NAS, but bad for use as part of a PC.

WD Purple

WD Purple is perfect for working with video surveillance systems, with the ability to connect up to 64 HD cameras in some drive models. This type of drive is considered the best in solving problems with video surveillance, since it is designed on the basis of a network video recorder and allows you to simultaneously record a large number of data streams. Reduced power consumption is a huge plus for systems operating 365 days a year, and silence and minimal vibration are ensured thanks to the Intel SIK system. The manufacturer guarantees 3 years of continuous operation of the drive. The high reliability of WD Purple is ensured by its resistance to external factors and the ability to operate at high temperatures.

WD Gold

It is best to build a data center or server on a model from the WD Gold line. They are thoroughly tested for compatibility with all popular server storage systems and are perfect for both small companies and corporate giants. The dual-drive head positioning system provides faster and more accurate data search on the disk. These disks are designed for a huge number of simultaneous requests from the network.

WD Re

WD Re (RAID edition) drives are specially optimized for operation in large RAID arrays with hot-swappable and expandable capabilities. With this in mind, they are equipped with special RAFF vibration prevention technology and STABLETRAC vibration protection technology. They are not designed for use as the main server drive and many simultaneous accesses like drives from the Gold series, but are more suitable for backup data storage. They have an increased rewriting resource and MTBF, which is important for large data centers. They can also operate at high temperatures and do not cut off power.

W.D. Se

WD Se drives are also designed to work together, but in a small array of 6 to 12 drives. They are more focused on small corporate customers and work in the SMB (file access protocol) segment. These disks are not designed for such volumes of rewriting and time resource as disks from the Re series, i.e. are their simplified and cheaper version. However, they are equipped with TLER array error correction technology and come with a 5-year warranty. They have a lower operating temperature threshold, but they also do not use a power cut.

Hard drive WD WD4002FYYZ
WD WD20PURX Hard Drive
HDD WD WD10EZEX

Western Digital colors indicate product range. Each color has its own characteristics, advantages, disadvantages and purpose.

We are all accustomed to choosing such devices based on two criteria - capacity and price. That is, if we have enough money in our pocket for an element with a certain capacity, we buy it.

In fact, everything is much more complicated and the concept under consideration directly relates to the choice of railway.

Contents:

Classification

Everything is much simpler than it might seem at first glance. The fact is that there are quite a few manufacturers of hard drives and Western Digital is one of them.

But the management of this company decided to take a non-standard approach to the naming of its product lines.

There are no words used here, just different colors. So there are such lines as WD Blue (that is, blue), WD Green (green), WD Black (black) and others.

The physical devices themselves have stickers in corresponding colors.

Table 1. Comparative characteristics

Name	Purpose	Peculiarities	Price for 1 TB HDD, US dollars	Average operating speed, rpm
Blue	Universal	Balance between speed and reliability	70$	7200
Green	“Ecological” devices for those who value a clean planet and quiet operation	Reduced energy consumption, noise and vibration levels, low operating speed	80$	5400
Black	for increased loads	Typically, Black series hard drives are used to install an operating system, heavy games and programs	90$	7200
Red	for 24/7 operation mainly in network devices	Improved protection against damage and overheating, reduced energy consumption	85$	5400 (manufacturer claims 7200)
Purple	Used in video surveillance systems	Many algorithms and programs are used to process video and improve its quality, vibration protection, while operating at low speed and high volume	80$	5400 maximum (usually much less)

Just based on these characteristics, you can say a lot about these devices, but we will try to consider them in more detail.

Blue

As stated above, this is a universal category that is suitable for all ordinary users. They are relatively inexpensive and fast.

The speed of work is achieved due to. In this case, options with 16 or more MB of memory are possible (there are also less, but today there is simply no point in such a small amount).

As for noise, it uses WhisperDrive technology to reduce it. They are best suited for simple everyday tasks, perhaps light office work.

For games and, as well as all kinds of computing, it is better to choose something more powerful.

The classic example of this line is WD10EZEX. Such a device costs just 72 dollars and cents. His The characteristics are as follows:

volume – 1 TB;
interface – SATA;
rotation – 7200 rpm;
buffer volume – 64 MB;
form factor – 3.5 inches.

Green

The main difference from all others is reduced energy consumption (40% lower according to company representatives).

Users also write that such drives are quite reliable to use.

It’s definitely worth saying that IntelliPower technology is used here, which, in fact, reduces power consumption.

Its purpose is to achieve an ideal ratio between rotation speed and data transfer.

They are one of the coolest of their kind. This means that their operating temperature is relatively low.

They also have very. But the speed of work often suffers greatly because of all this.

As an example of “green” wheels, we can recall the WD20EZRX. The features of this sample are::

volume – 2 TB;
interface – SATA;
buffer volume – 64 MB;
form factor – 3.5 inches.

The manufacturer does not indicate the rotation speed and simply writes “IntelliPower”. In practice, it is 5400 rpm.

Black

These devices are quite suitable for performing all sorts of heavy tasks, such as mathematical modeling, and so on.

They can be used at home, but they are even too powerful for working on office tasks. on one of the HDDs WD Black will simply fly, like other similar programs.

7200 rpm is the minimum, sometimes more. In addition, such devices have excellent random access times.

They are also distinguished by low operating temperatures and excellent vibration protection.

Thanks to this and other interesting features, maximum operating speed is achieved.

The volume here can reach 64 MB, which, again, increases performance.

It is also worth paying attention to the dual-drive system for determining the location of the drive heads.

Due to this, very high accuracy of head placement is achieved, which is very important when working with data.

An example of this line is the WD10JPLX model, priced at $95. You can buy it in some stores for $50, but usually more (100 bucks or more). Here its features:

volume – 1 TB;
interface – SATA;
rotation – 7200 rpm;
buffer volume – 32 MB;
form factor – 2.5 inches.

WD Black WD10JPLX

Red

Designed to work with even greater loads than “black” ones. They are usually used in large offices, servers and similar devices.

They are unlikely to be suitable for home use, unless we are talking about NAS systems. Then WD Red can be used in small offices.

If you don’t know what systems we are talking about, then you don’t need such devices.

Among the advantages: increased reliability, as well as protection against damage, vibration and excessive temperature. Interestingly, the rotation speed is usually lower than what the manufacturer claims.

Let's take the WD60EFRX model as an example. It is specifically intended for servers or network storage.

Price: $250 (may be more or less depending on the store). Her characteristics:

volume – 6 TB;
interface – SATA;
buffer volume – 64 MB;
form factor – 3.5 inches.

Here, next to the rotation, it also says “IntelliPower”.

Purple

The main and for some the only feature of the devices from this section is the use of special AllFrame technology.

It provides high reliability in systems and security in premises.

Image decay, which usually leads to loss of quality or complete erasure of recordings, is virtually eliminated on these drives.

This became possible thanks to the use of a large number of software solutions from the manufacturer

They can work around the clock without any interruptions. This is eloquently confirmed by the recently released 100PURZ model, which costs about $500. Here it is peculiarities:

volume – 10 TB;
interface – SATA;
rotation – 5400 rpm;
buffer volume – 256 MB;
form factor – 3.5 inches.

SE, RE and VelociRaptor

In addition to the “color” lines of hard drives, there are three more categories. Their characteristics can be seen in Table 2.

Table 2. Characteristics of WD SE, RE and VelociRaptor

WD VelociRaptor WD5000HHTZ 500 GB

Below you can see an overview of two models from the categories described above.

WD series of consumer hard drives for various purposes are marked in several colors. Blue is the basic version of desktop HDDs with a spindle speed of 7200 rpm. Black - seven-thousanders with increased performance and a 5-year warranty. Green - energy-efficient discs, spindle speed 5400 rpm. The division is intuitive for any inexperienced buyer. “Green” means environmentally friendly, consumes little energy and heats up little. “Black” - solid, fast and expensive. “Blue” is neither this nor that, the color of satisfaction with the price/performance ratio. Previously, color markings accompanied the general Caviar brand, but now the inappropriate gastronomic associations have disappeared. Let us note that if Western Digital were a Russian company, branding could be deployed in this direction. For example, “red caviar”, “black caviar” and “eggplant caviar”...

Be that as it may, in the WD hard drive lines we have an example of a simple and clear presentation of a complex product to the buyer. Until now, only one of the basic colors of the RGB standard was free in the palette - red, and now it has been given to a line of hard drives specifically designed for home or small office NAS. In this case, the connection between the specifics of the product and the psychological meaning of the color label is no longer obvious, but in order to announce a new product to the world, red is the most important thing. And there is no need to explain what associations this color evokes among Russian buyers. There are no indifferent people.

Bright advertising message will not interfere at all with a product such as a hard drive for a SOHO (small office, home office) NAS. After all, it seems that this is the only application for which the end user often buys HDDs. The bulk of desktop HDDs are supplied as part of ready-made computers, 2.5-inch models even more so. Server hard drives are purchased by enterprise IT services. But the owner of a home NAS is guaranteed to go to the store to buy a hard drive on his own. WD decided to take it into circulation.

⇡ Technical specifications

For NAS, as a rule, they choose some kind of “green” hard drive with a spindle speed of 5400-5600 rpm. So why is “red” better? WD Red drives are really the closest to the WD Green desktop series. For both of them, instead of rotation speed, the specifications indicate the phrase IntelliPower. This means that for each HDD instance in production, the speed suitable for it is selected. For all drives with IntelliPower, this parameter fluctuates around 5400 rpm, and only Western Digital knows exactly how much. The boundaries of the corridor within which devices are “calibrated” are also unknown.

In total, the Red series has so far released three models with capacities from 1 to 3 TB. They also promise the appearance of a 4-terabyte one. It is noteworthy that all three are built on 1 TB platters. In other series, Western Digital managed to introduce such plates only for one-terabyte Green and Blue models. Hence the sequential access speed is around 150 MB/s - even higher than that of the bulk of WD Black.

Western Digital does not disclose the response time of the drives. There is only a phrase on the official website that WD Red has “optimized search”, which leads to “best-in-class performance”. Well, we'll check that later.

Specifications

Manufacturer	Western Digital	Western Digital	Western Digital
Series	Red	Red	Red
Model	WD10EFRX	WD20EFRX	WD30EFRX
Form factor	3.5 inches	3.5 inches	3.5 inches
Interface	SATA 6 Gb/s	SATA 6 Gb/s	SATA 6 Gb/s
Capacity, GB	1000	2000	3000
Spindle rotation speed, rpm	~5400	~5400	~5400
Data recording density, GB/plate	1000	1000	1000
Number of plates/heads	1/2	2/4	3/6
Buffer volume, MB	64	64	64
Sector size, bytes	4096	4096	4096
Performance
Avg./Max. sequential read speed, MB/s	150/ND	145/ND	145/ND
Avg./Max. sequential write speed, MB/s	150/ND	145/ND	145/ND
Avg./Max. random read speed, MB/s	ND	ND	ND
Avg./Max. random write speed, MB/s	ND	ND	ND
Avg./Max. access time - read, ms	ND	ND	ND
Avg./Max. access time - recording, ms	ND	ND	ND
Track change time: read/write, ms	ND	ND	ND
Internal data transfer rate, Mbit/s	ND	ND	ND
Reliability
Mean time between failures, h	1 000 000	1 000 000	1 000 000
Number of head parking cycles	600 000	600 000	600 000
Availability 24x7	Yes	Yes	Yes
physical characteristics
Power consumption: standby/read-write, W	0,6/3,7	0,6/4,4	0,6/4,4
Typical Noise Level: Idle/Searching	21/22 dBA	23/24 dBA	23/24 dBA
Shock resistance: disk on/disk off	60 G (2 ms) / 250 G (1 ms)	60 G (2 ms) / 250 G (1 ms)	60 G (2 ms) / 250 G (1 ms)
Overall dimensions: LxHxD, mm	147x101.6x26.1	147x101.6x26.1	147x101.6x26.1
Weight, g	450	600	640
Warranty period, years	3	3	3
price, rub.	No data	No data	No data

The key difference between WD Red and Green is a few hardware features and firmware tweaks that make Red a more suitable option for NAS use.

Guaranteed work 24x7. The point speaks for itself. Most desktop drives are generally not designed for continuous load.

Increased reliability. The average time between failures for WD Red is 1 million hours. Although this does not mean that a single hard drive will work without failure for 114 years. Just one out of 114 disks will fail in a year. Unfortunately, WD does not indicate this parameter for the “green” series, but you can compare the estimated number of head parking cycles: 600,000 for Red and 300,000 for Green.

Increased resistance to vibration. Everything is clear, no comments.

3D balancing. Like car wheels. The block of magnetic plates is secured to the spindle with several screws. By adjusting their length, vibration and noise can be reduced.

To conclude the conversation about hardware, we will highlight the issue of energy consumption and heat dissipation. The manufacturer doesn't list low heat as a particular benefit of the Red, but the product's official web page shows IR images comparing it to an unnamed competitor. Based on the shape of the ribs of the “can” and the printed circuit board, it is easy to determine that this is one of the recent “Barracudas” (generation 7200.14). It’s not a very fair comparison, because all the Barracudas today are seven-thousanders. On the other hand, Seagate itself is to blame for killing its “green” line.

In the pictures, the WD “red” HDD is colder than its unnamed competitor

⇡ Specialized firmware

The manufacturer calls the firmware for WD Red drives NASWare. This is how it differs from what is “sewn” into ordinary “green” HDDs.

No frequent head parking. Desktop drives often set a very short idle timeout, after which the head block is parked (APM - Advanced Power Management parameter). In principle, this saves a little energy, but at the same time reduces the reaction time during subsequent handling and uses up the allocated reserve of parking cycles (see above). By default, WD Red does not park heads at all during operation (this happens automatically when the power is turned off).

No engine stop. By default, the firmware does not allow WD Red to stop the engine: spindown (standbly) timer value is zero. Which again maintains a stable disk response time.

Error correction timeout. WD Red has an SCT ERC (SMART Command Transport Error Recovery Control) option. WD calls it its own: Time Limited Error Recovery (TLER). This is a fundamental parameter for disks in a RAID array, controlling the behavior of the hard disk when bad sectors are detected. In principle, there are two options for reacting to such an event. Desktop drives stubbornly try to read data - this in extreme cases leads to the disk sinking into itself for 20 minutes. For disks in a RAID array with redundancy, this is unacceptable: if the HDD becomes dull for a long time, the controller will simply throw it out of the array. Therefore, it is better to signal “I’m alive” to the controller as soon as possible, and the lost data will be restored from neighboring disks. In WD Red, the default error correction time is 7 seconds (like the WD RE series, by the way).
Note that APM (parking timeout) of heads and standby timer (motor stop timeout), in principle, are regulated on other hard drives using utilities that send ATA commands, although we cannot guarantee their correct support in all cases Can. It’s just that with WD Red they are already adjusted correctly, and there is no need to manually adjust anything. But SCT ERC is rare for desktop drives, which is why they are not recommended for installation in redundant arrays.

Support ATA Streaming Feature Set. A small bonus for broadcasting streaming media content. If the NAS operating system can handle these commands, then they can guarantee uninterrupted flow, while the drive will also serve other requests.

⇡ Prices

Western Digital charges a significant fee for the benefits of WD Red. Models with a capacity of 1, 2 and 3 TB in Moscow online stores cost an average of 3,000, 4,200 and 6,100 rubles. For comparison: prices for models of similar volume from the WD Green series are 2,600, 3,400 and 4,700 rubles. respectively.

Decoding the markings of internal WD hard drives:

(1)WD (2)000 (3)0 (4)A (5)B (6)C (7)D

1 . Western Digital.

2 . One or three digits are used to determine the disk capacity. The volume is measured in the quantities specified in paragraph 4.

3 . 0 - serves to highlight some features. For example, the WD5001ABYS disk differs from the WD5000ABYS only in that the former has a perpendicular recording method versus the parallel one of the latter.

4 . A letter describing the value in which the volume specified in paragraph 2 is measured and the disk form factor:

A – gigabyte/3.5”,
B - gigabyte/3.5" or gigabyte/2.5",
C - 3.5",
E – terabyte/3.5”,
F – 10 gigabytes/3.5”,
G/H - gigabyte/3.5",

5 . A letter describing the market segment for which the drive is intended and the family to which it belongs:

A – Desktop/Caviar;
B – Enterprise/RE2 (3-plate)/RE2-GP;
D – Enterprise/Raptor;
E, P — Mobile/Scorpio Blue
G – Enthusiast/Raptor X;
J - Mobile/Scorpio Black
L - Enterprise/VelociRaptor;
V - Audio-Video (Audio and Video Equipment);
Y – Enterprise/RE2 (4-plate)/RE2-GP/RE3/RE4.

6 . Letter describing the speed and size of the cache:

B – 7200 rpm and 2 MB cache;
C – Caviar Green and 16 MB cache;
D - Caviar Green and 32 MB cache;
F – 10000 rpm and 16 MB cache;
G – 10000 rpm and 8 MB cache;
H - 10000 rpm and 32 MB cache;
J – 7200 rpm and 8 MB cache;
K – 7200 rpm and 16 MB cache;
L - 7200 rpm and 32 MB cache;
P – RE2-GP and 16 MB cache;
Y – RE2/RE3 and 16 MB cache or RE4 and 64 MB cache;
R - Caviar Green, 64 MB cache and Advanced Format;
S/E - 7200 rpm and 64 MB cache. V - 5400 rpm and 8 MB

7 . Letter describing the hard drive interface:

B – PATA-100;
E—PATA-133;
D – SATA-150;
S – SATA-300;
X - SATA-600.

Old markings

The above is a relatively new way of marking. Previously, a template was used in which pp. 4-5 were absent; two or three digits were allocated for the disk size (volume was measured in gigabytes); the following digit was reserved for all families; in paragraph 6, the letter L was also used (7200 rpm/2 MB), and the letter P had a different meaning - 7200 rpm/8 MB; in paragraph 7 the letter R (SATA-150) was also used.

For example: WD800JB: 80 GB, 8 MB buffer, 7200 rpm, IDE, and WD800JD: 80 GB, 8 MB buffer, 7200 rpm, SATA; WD5000AAKS: 500 GB, 3.5", Caviar family, 16 MB, 7200 rpm, SATA2; WD5000BEVT: 500 GB, 2.5", 8 MB, 5400 rpm, SATA2.

Note:

WD10EADS-00P8B0 and WD15EADS-00P8B0 drives may have strong visible slowdowns at random times during the write/read processes, which are difficult to diagnose/catch when claiming under warranty.
WDxxEARS disks have Advanced Format, which imposes special features on their operation.

FAQ

1. I heard that WD hard drives have a ramp. What is it for?

Indeed, some WD drives have a ramp. The head block is located on it when the plates unwind, stop, or when the drive is turned off. This helps to increase the shock resistance of the drive when not in use, and in the long term, operation reliability increases due to reduced contact and wear of plates and heads.

2. In what mode are drives with the SATA-300 interface supplied?

Hard drives with the index “S” (SATA-300) are sold with the SATA-300 mode enabled and the Spread Spectrum Clocking (SSC) function disabled.

3. What are jumpers used for?

Closing contacts 1-2 leads to the inclusion of the Spread Spectrum Clocking function.
Closing contacts 3-4 will enable Power Management mode (PM2 enable mode: to enable power supply in standby mode, place a jumper on pins 3-4. This mode will provide controlled spin-up using the spin-up command in accordance with the ATA standard and is intended mainly for running servers /workstations operating in multi-disk configurations.
Important! PM2 mode requires a compatible BIOS that supports this feature. If PM2 is enabled and not supported by the BIOS, the hard drive does not spin up and is therefore not detected by the system.
Note: The PM2 function does not work on all WD SATA drives).
Closing contacts 5-6 will enable SATA150 transfer mode.
Closing contacts 7-8 will lead to a shift of one sector of partitions in disks with Advanced Format.

4. Some WD drives have two power connectors: SATA and Molex. Which one should I connect to?

You can connect power to either one, but not to both at the same time.

5. All hard drives that I have seen have a board with electronics on the bottom. I bought WD, but this board is empty! This is fine?

For WD hard drives, the board with electronics is upside down. This technique, according to WD, allows you to solve two problems at once - protect the chips from external influences and ensure their cooling. Since the microcircuits are located under a layer of PCB, they cannot be accidentally damaged by a sharp object when unpacking and installing the hard drive into the case. They are also protected from static electricity. Between the printed circuit board and the case there is a layer of thermally conductive material, thanks to which the microcircuits can transfer heat to the metal.

6. Why are acceleration sensors installed on WD electronics boards?

The boards contain one or two acceleration sensors, which are used to detect the vibration of the drive during operation and allow the controller to compensate for the movement/acceleration of the actuator caused by these vibrations. They allow you to quickly and accurately get onto the desired path even in conditions of increased vibration (RAFF technology - clause 17d).

7. What warranty does WD give for its desktop hard drives?

3 years on the Caviar Green/Blue series and 5 years on the Caviar Black, RE and Raptor series.

8. What are the differences between the Caviar Green, Caviar Blue, and Caviar Black series?

Green - slow, quiet, cool, low-power drives. Spindle rotation speed is in the range of 5000-5600 rpm (i.e. the speed is fixed, but may vary for different models). Great for storing data. They park idle (they have a ramp). The parking function may interfere with the user, then it needs to be disabled using the wdidle utility.
Blue - regular general purpose disks. Spindle rotation speed - 7200 rpm.
Black - positioned as high-performance wheels. Differences from Blue: they have a dual-core processor (marketing says “two processors”); may have more cache than Blue-classmate; air spoiler plates cutting air flow; double spindle mounting (bottom on the platform with the motor and top on the cover); double actuator on some models; 5 years warranty.

9. What are the differences between Raptor series wheels and Caviar Blue/Black series wheels?

The main difference is the Raptor's rotation speed is 10,000 rpm versus 7,200 for the Caviar. As a consequence of this, Raptor's access time is significantly shorter. The warranty on Raptor wheels is 5 years.

The Raptor X is a regular Raptor with a large clear lens on the top cover through which you can view its operation.

VelociRaptor drives also have 2.5" platters and a 2.5" format, which further reduces access time.
Some VelociRaptor models (WD3000GLFS and WD3000HLFS) can be installed in both 2.5" and 3.5" bays. To do this, use a 3.5" metal radiator supplied with the disk, which, together with the drive mounted in it, is screwed with standard screws in the 3.5" compartment.

10. What are the differences between the Caviar RE series and Caviar Green/Blue/Black?

RE stands for "RAID Edition". RE series drives have an increased MTBF, different firmware, and support TLER technology (see paragraph 17c). The manufacturer is positioned for professional applications, for example, in data storage systems or servers/workstations when working in RAID arrays. The warranty on them is 5 years.
Have two processors; vibration compensation system; head flight adjustment system; TLER system; ramp.
The RE-GP Series are Green Series drives with RE Series features.

11. What is the difference between WD5000AAKS and WD5000KS drives?

Their main difference (and this applies to all models, the markings of which are distinguished only by the presence of “AA” in one and the absence of another) is that a disk with “AA” has a significantly higher recording density than a disk without it. Such drives have fewer platters, which means they are faster, consume a little less energy and have a slightly lower temperature (for example, the WD5000KS contains four platters, and the WD5000AAKS has three). Naturally, disks with “AA” are newer.

12. Is it worth buying an RE hard drive for your home system?

I note that, in my opinion, the above features of this series at home practically do not provide any advantages. Now let's look at the strategy for the behavior of different disks on different systems.
Regular desktop drives are designed to operate independently, and when connected to a RAID controller, they are not even aware of its presence. If errors occur during the operation of the drive, its firmware tries to correct them independently using the built-in error correction system. If the repair process takes more than 8 seconds (although there is no standard for controller wait time, these 8 seconds are typical for most RAID controllers), then the RAID controller will consider the disk to be faulty and turn it off from the array, which can lead to unpleasant consequences.
For a WD hard drive using TLER technology (item 18c), the situation is different. If an error occurs, the drive tries to correct it on its own for 7 seconds, and then transmits information about the error to the RAID controller, which decides whether to fix it now or leave it for later.
However, if the opposite situation occurs (a hard drive with TLER operates outside of RAID), the drive “thinks” that it is connected to the RAID controller, and if it is impossible to correct the error using its own means, it admits its powerlessness and offers the controller to solve the problem. But he’s not there...
Therefore, Western Digital itself does not recommend installing a WD hard drive with TLER in a system where RAID is not planned.

13. What is the maximum temperature of WD hard drives?

For modern WD hard drives, the maximum permissible temperature is 60 degrees on the surface of the can. However, this does not mean that the drive will be able to operate for a long time at such heating.

14. All programs show that my WD hard drive has a temperature of 70 degrees. What to do?

According to Western Digital technical support, hard drives manufactured from October 25, 2005 to mid-April 2006 had problems with calibrating the temperature sensor, and therefore it shows a temperature higher than the real one by 20 degrees or more. The problem can be resolved by changing the firmware.

15. Does WD have perpendicular recording discs?

This recording method is used in the WD7500AAKS and all newer models of all series.

16. Is it true that the spindle speed of hard drives from the Caviar Green family varies from 5400 to 7200 rpm depending on the load?

No, this is just a marketing ploy by the manufacturer. In fact, the situation is this: for the Caviar Green WD family, the possibility of different spindle speeds on different models is declared, but on each specific drive this speed is CONSTANT, which is confirmed by a quote from the description of the IntelliPower technology: “For each GreenPower drive model, WD may use a different ,invariable RPM" (http://www.westerndigital.com/en/library/sata/28).
Because WD does not disclose what the true speed of the released models is, hiding behind the meaningless IntelliPower label, you have to rely on test results. So, according to various tests, the assumption is confirmed that all Caviar Green hard drives now have 5400 (much more often) and 5000 (less often) rpm (for example, http://www.storagereview.com/1000.sr?page=0 %2C2, http://www.silentpcreview.com/article786-page2.html). Thus, the current “green” WD wheels have a speed of 5400 or 5000 rpm, which DOES NOT CHANGE during operation.

17. Where is the temperature sensor located on WD drives?

Inside the jar in the area marked with a red circle. It is the temperature of this sensor that is displayed in S.M.A.R.T.

18. What proprietary technologies does WD have?

a) SecureConnect – a more reliable connection of SATA connectors (requires a special cable from WD);
b) FlexPower – the presence of both SATA and molex power connectors;
c) TLER (RAID-specific Time-Limited Error Recovery) – allows you to reduce the time required to recover read errors, reduces the percentage of RAID failures (see clause 13);
d) RAFF (Rotary Accelerator Fead Forward) - optimizes the performance of drives when operating in vibration environments, for example, in rack-mounted servers and network storage.
e) SoftSeek - reduces actuator noise during positioning, optimizing the shape of the control signal supplied to the head drive when moving them over long distances;
f) IntelliPark - parking heads in idle mode (used in Caviar Green);
g) IntelliSeek - bringing the head unit to the desired sector just at the moment it arrives under the head, instead of a frantic flight to the track and further waiting for the desired sector.

19. How to use the wdidle program to change the hard drive parking parameters when idle?

wdidle needs to be copied to a bootable DOS CD/DVD/flash drive, switch the SATA controller to IDE mode, disconnect other drives just in case, and boot from bootable media. Next, run the program with the appropriate parameters:
/S - sets a timer for the time after which the disk parks the heads if there are no calls to it, in hundreds of milliseconds (the parameter can be equal to from 1 to 255). By default it is 80, i.e. 80*100 ms=8000 ms=8 s;
/D - prohibits parking;
/R - displays the current timer value;
/? — displays utility help.

20. What is technologyAdvanced Format?

This is the technology used in the production of some series of new terabyte HDDs. Its essence lies in the fact that the surface of the disks is divided into sectors of non-standard size - 4 KB versus 512 bytes of regular ones. This is good for working with large files and, on the contrary, negative when working with small files. Thus, it is better to use such HDDs only for creating file storage, but not for actively working with the disk, otherwise this could lead to a decrease in performance.

In addition, for such disks to work with Windows XP, they can only be formatted using a special WD Align utility, otherwise a catastrophic decrease in performance will again be noticeable.

21. How can I find out the number of platters and heads in various WD hard drives? There is nothing in the specifications.

WD is often accused of not providing information about the number of heads and platters in specific drives to the end user. Therefore, you have to get this information from reviews. Here's what we found out:

A) disks up to 160 GB:

WD400Bx – 1 plate/1 head;
WD800xx – ½;
WD1200xx – 2/3;
WD1200AAxx – ½;
WD1600xx – 2/4;
WD1600AAxS (B) – ½;

b) disks with a capacity of 250-400 GB:

WD2500xx – 3/6;
WD2500AAxS (B) – 2/4, with “B3A”, “B4A”, “VSA” or “VTA” in the model number (MDL) – ½;
WD2500AAKX - ?/?;
WD2502ABYS - ½;
WD2503ABYX - 1/1;
WD3000xx - 3/6;
WD3200xx - 3/6;
WD3200AAxS (B) – 2/4, with “B3A” or “B4A” – ½;
WD3200AAKX - ?/?;
WD3200AALX - ?/?;
WD3202ABYS - ½;
WD4000xx - 4/8;
WD4000AAxS (B) – 3/5;

V) 500 GB disks:

WD5000KS - 4/8;
WD5000AAxS (B) – 3/6, with “A7B”, “A8B” or “L9A” – 2/4, with “M9A” or “V1A” – ½;
WD5000AAKX - ?/?;
WD5000AALX - ?/?;
WD5001AALS - 2/4;
WD5002AALX - ?/?;
WD5000AACS – 2/4 and 2/3;
WD5000AADS - ½;
WD5000ABPS - 2/4;
WD5000YS - 4/8;
WD5000ABYS - 3/6;
WD5002ABYS - 2/4;
WD5003ABYX - ½;

G) disks with a capacity of 600-800 GB:

WD6000HLHX - 3/?;
WD6400AAKS — 2/4, with “H2B” — 2/3;
WD6401AALS - 2/4;
WD6400AALX - ?/?;
WD6402AAEX - 2/3;
WD6400AACS - 2/4;
WD6400AADS - 2/3;
WD6400AARS - 2/3;
WD7500AAKS – 4/8;
WD7501AALS - 3/5;
WD7500AALX - ?/?;
WD7502AAEX - ?/?;
WD7500AACS – 3/6, with “DB6” – 3/5;
WD7500AADS – 2/3;
WD7500AYPS - 3/6;
WD7502ABYS - 3/5;
WD8000AARS - 2/3;

d) disks with a capacity of 1-1.5 TB:

WD1001FALS - 3/6, with "E3A" or "U9B" - 2/4;
WD1002FAEX - 2/4;
WD10EALS - 2/4;
WD10EALX - ?/?;
WD10EACS – 4/8, with “D6B” – 3/6;
WD10EADS – 3/6, with “M2B” – 2/4, with “P8B” – 2/4, 5000 rpm;
WD10EARS - 2/4, with "Z5B" - 5000 rpm;
WD1000FYPS - 4/8;
WD1002FBYS - 3/6;
WD1003FBYX - 2/4;
WD15EADS - 3/6 and 4/7;
WD15EARS - 3/6;
WD1501FASS -3/6;
WD1502FAEX - ?/?;
WD1502FYPS - 3/6;
WD1503FYYS - 3/6;

e) disks with a capacity of 2 TB and higher:

WD20EADS - 4/8;
WD20EARS - 4/8, with "MVWB" - 3/6;
WD2002FYPS - 4/8;
WD2001FASS - 4/8;
WD2002FAEX - ?/?;
WD2003FYYS - 4/8;
WD25EZRS - ?/?;
WD30EZRS - 4/8.