The capacity of hard drives continues to increase, but the growth rate has been steadily declining in recent years. So, in order to release the first 4 TB drive after 2 TB HDDs went on sale, the industry spent only two years, it took three years to conquer the 8 TB mark, and to double the capacity of a 3,5-inch hard drive once succeeded in only five years.
The latest breakthrough was realized thanks to a whole list of innovative solutions. Today, even conservatives like Toshiba, which until recently refused helium, are forced to produce hard drives in sealed cases, and the number of platters per spindle has increased to nine pieces - although once, and for a long time, five platters were considered a reasonable limit. In specific niches, the so-called technology is used. tiled recording (SMR, Shingled Magnetic Recording), in which the tracks of the sectors on the plate partially overlap. Finally, in order to push the hard drive capacity limit from 14TB to 16TB without using SMR, manufacturers had to introduce one of the promising technologies, a gradually shrinking list of which we reproduce in annual , β track reading by several heads simultaneously (TDMR, Two-Dimensional Magnetic Recording). Further movement will sooner or later require more extensive changes in the basics of HDD operation - such as heating the plate with a laser or microwaves (HAMR / MAMR, Heat / Microwave-Assisted Magnetic Recording) at the moment the recording head passes.
However, it is easy to see that all the described techniques are primarily aimed at increasing the recording density and increasing the volume on a single spindle, although many of them have a beneficial side effect in the form of an increased speed of linear reading and writing data. According to this parameter, modern HDDs have broken beyond the 250 MB / s border and are already comparable to early consumer SSDs. But the speed of access to random sectors of magnetic disks almost does not progress, and in terms of volume, the number of operations per second becomes only less. At the same time, there are increased requirements for fault tolerance, because the more data is stored on one spindle, the more important it is not to lose it and the longer it takes to restore it.
But the creators of magnetic storage devices also found an answer to this challenge. We took three hard drives from 14 to 16 TB to see how 64-year-old technology is adapting to the realities of 2019, and noticed several trends. Champion samples of modern 3,5-inch hard drives, produced for rack servers and storage systems, have something in common with solid state drives - from sector addressing principles to direct integration of flash microcircuits into the local memory stack. And consumer models, in turn, have become closer in their characteristics to server counterparts, and even the description βdesktop HDDβ does not say much about the speed and reliability of the device. But the purpose of this review is not limited to generalities. We're going to find out how new trends in hard drive design translate into solid performance numbers.
Specifications of test participants
Before we start analyzing the test results, it is worth carefully studying the characteristics of the devices with which we will be dealing. This time there are not as many of them as it usually happens in our group tests, but we have met the main conditions without which the comparison of hard drives cannot claim to be complete. The review included products from all three manufacturers - Seagate, Toshiba and Western Digital, and they belong to different categories: consumer and server. The main characteristics that unite them are a volume of 14 or 16 TB, a sealed case filled with helium, and a spindle speed of 7200 rpm. And for comparison with the heavyweights, three smaller devices already familiar to us (10 and 12 TB), designed for use in servers, home or office NAS, are participating in the test.
| Manufacturer | Seagate | Toshiba | Western Digital | |||
|---|---|---|---|---|---|---|
| Π‘Π΅ΡΠΈΡ | BarraCuda Pro | Exos X10 | Iron Wolf | MG08 | S300 | Ultrastar DC HC530 |
| Model number | ST14000DM001 | ST10000NM0016 | ST12000VN0008 | MG08ACA16TE | HDWT31AUZSVA | WUH721414ALE6L4 |
| Form Factor | 3,5 in | 3,5 in | 3,5 in | 3,5 in | 3,5 in | 3,5 in |
| Interface | SATA 6Gb / s | SATA 6Gb / s | SATA 6Gb / s | SATA 6Gb / s | SATA 6Gb / s | SATA 6Gb / s |
| Capacity, GB | 14 000 | 10 000 | 12 000 | 16 000 | 10 000 | 14 000 |
| Configuration | ||||||
| Spindle speed, rpm | 7 200 | 7 200 | 7 200 | 7 200 | 7 200 | 7 200 |
| Usable data recording density, GB/platter | 1 750 | 1 429 | 1 500 | 1 778 | 1 429 | 1 750 |
| Number of plates/heads | 8/16 | 7/14 | 8/16 | 9/18 | 7/14 | 8/16 |
| Sector size, bytes | 4096 (512 byte emulation) | 4096 (512 byte emulation) | 4096 (512 byte emulation) | 4096 (512 byte emulation) | 4096 (512 byte emulation) | 4096 (512 byte emulation) |
| Buffer size, MB | 256 | 256 | 256 | 512 | 256 | 512 |
| Performance | ||||||
| Max. sustained sequential read speed, MB/s | 250 | 249 | 210 | ND | 248 | 267 |
| Max. sustained sequential write speed, MB/s | 250 | 249 | 210 | ND | 248 | 267 |
| Average seek time: read/write, ms | ND | ND | ND | ND | ND | 7,5/ND |
| fault tolerance | ||||||
| Estimated load, TB / g | 300 | ND | 180 | 550 | 180 | 550 |
| Fatal read errors, number of cases per amount of data (bits) | 1 / 10 ^ 15 | 1 / 10 ^ 15 | 1 / 10 ^ 15 | 10 / 10 ^ 16 | 10 / 10 ^ 14 | 1 / 10 ^ 15 |
| MTBF (mean time between failures), h | ND | 2 500 000 | 1 000 000 | 2 500 000 | 1 000 000 | 2 500 000 |
| AFR (probability of failure per year), % | ND | 0,35 | ND | ND | ND | 0,35 |
| Number of head parking cycles | 300 000 | 600 000 | 600 000 | 600 000 | 600 000 | 600 000 |
| physical characteristics | ||||||
| Power consumption: idle / read-write, W | 4,9/6,9 | 4,5/8,4 | 5,0/7,8 | ND | 7,15/9,48 | 5,5/6,0 |
| Noise level: inactivity / search, B | ND | ND | 1,8/2,8 | 2,0/ND | 3,4/ND | 2,0/3,6 |
| Maximum temperature, Β°C: disk on / disk off | 60/70 | 60/ND | 70/70 | 55/70 | 70/70 | 60/70 |
| Shock resistance: drive on / drive off | ND | 40 g (2 ms) / 250 g (2 ms) | 70 g (2 ms) / 250 g (2 ms) | 70 g (2 ms) / 250 g (2 ms) | 70 g (2 ms) / 250 g (2 ms) | 70 g (2 ms) / 300 g (2 ms) |
| Overall dimensions: L Γ H Γ D, mm | 147 Γ Γ 101,9 26,1 | 147 Γ Γ 101,9 26,1 | 147 Γ Γ 101,9 26,1 | 147 Γ Γ 101,9 26,1 | 147 Γ Γ 101,9 26,1 | 147 Γ Γ 101,6 26,1 |
| Mass, g | 690 | 650 | 690 | 720 | 770 | 690 |
| Warranty period, years | 5 | 5 | 3 | 5 | 3 | 5 |
| Retail price (USA, without tax), $ | From 549 (newegg.com) | From 289 (newegg.com) | From 351 (newegg.com) | ND | From 301 (newegg.com) | From 439 (amazon.com) |
| Retail price (Russia), rub. | From 34 348 (market.yandex.ru) | From 17 498 (market.yandex.ru) | From 26 320 (market.yandex.ru) | ND | From 19 784 (market.yandex.ru) | From 27 495 (market.yandex.ru) |
The first model in our modest collection of immodest hard drives, the BarraCuda Pro 14TB is a desktop and DAS drive, but not a simple one, but a βprofessional oneβ. On the one hand, this means that the BarraCuda Pro is subject to the typical limitations of desktop hard drives. For example, it is not intended for combining into RAID arrays, because for this it is desirable to have TLER (Time-Limited Error Recovery) - a firmware setting that prevents the HDD from flying out of the array due to the microcontroller's long attempts to read the problem sector. On top of this, the BarraCuda Pro chassis is not well suited to work in a shelf or NAS with multiple cages, because it does not have rotational vibration compensation.
But on the other hand, unlike most other desktop hard drives, HDDs of this brand have an increased annual load resource - up to 300 TB of rewriting, are ready to work 24/7 and are accompanied by a five-year warranty. You probably won't have to complain about speed either (at least in tasks with predominantly linear data access): thanks to eight 1,75 TB platters, the device achieves a sustained throughput of 250 MB / s. In addition, the manufacturer promises that the random access speed in BarraCuda Pro should be higher compared to ordinary desktop drives, and power consumption, on the contrary, is lower than that of most 3,5-inch models. However, we will check all Seagate statements.
In order to conquer such a high level of data density within the framework of standard perpendicular recording without the use of niche SMR (Shingled Magnetic Recording) technology, Seagate had to introduce one of the promising methods that we write about in our blogs year after year. , - so-called. two-dimensional recording (Two-Dimensional Magnetic Recording). But contrary to its name, TDMR is in no way related to the data recording procedure as such and is intended to increase the signal-to-noise ratio under conditions of high track density on a magnetic platter by simultaneously reading a track with two read heads: the latter are separated in space in such a way that the field captures neighboring tracks, and it becomes easier to compensate for interference. In the future, hard drives with TDMR will gain even more heads, and along with the reliability of data reading, its speed may increase, but this is still a matter of the future.
BarraCuda Pro drives differ in many ways from their lower-end siblings without the Pro box, starting with the fact that all HDD manufacturers have standard desktop models stuck at 6-8 TB. The BarraCuda Pro drive can rather be described as the offspring of the Seagate server branch, which is devoid of functions related to working in arrays. But as a result, the price of the device soared to the level of corporate models, or even higher: in Russia, a 14-terabyte model cannot be found cheaper than 34 rubles, and on US retail sites - $348. Even Seagate nearline models of the same volume cost less - from $549 or 375 rubles.
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The next test drive, the 14TB Ultrastar DC HC530, was a nearline drive that represented the best of Western Digital engineers until the new 16TB model arrived. And in the practice of 3DNews, it became the first Ultrastar hard drive without the usual letters HGST in the name: the company transferred all server models under its own brand after the assets of HGST were completely dissolved in the merged corporation. In its key characteristics, this device is similar to the BarraCuda Pro of the same volume: inside the sealed housing of the Ultrastar DC HC530 there are also eight magnetic plates with a usable capacity of 1750 GB, and reading data from densely spaced tracks is provided by TDMR technology. But in terms of other parameters and a variety of additional functions typical of corporate HDDs, Ultrastar DC HC530 cannot be put on the same level with desktop models, even though BarraCuda Pro is not a typical representative of its category.
So, the usable write density on the BarraCuda Pro and Ultrastar DC HC530 platters is the same, as is the spindle speed, but the WD product guarantees a higher sustained linear read and write speed of data - up to 267 MB / s (it is not clear where the difference came from , but tests will show if it actually exists). Random access delays are reduced by a new, third-generation two-stage actuator and a large 512 MB buffer, and most importantly, Media Cache - reserve zones for fast block writing scattered over the surface of the platters. The latter feature makes modern nearline drives related to solid state drives, in which there is also a variable ratio between physical sectors and logical blocks. And starting with the 10TB Ultrastar DC HC330 models, WD also uses a small amount of flash memory to cache write operations. Note that along with (potentially) extremely high performance by the standards of magnetic drives, the WD product is distinguished by moderate power consumption - in fact, this is the device with the lowest power consumption among all test participants, judging by its passport parameters.
Drives of this class are built with the expectation of continuous operation in a server rack: double-sided spindle mounting, rotational vibration compensation - these and other design features of the Ultrastar DC HC530 made it possible to bring the design load of the disk up to 550 TB / year, and the MTBF is typical for nearline -models 2,5 million hours. In the unlikely event that a firmware update fails, a spare chip is soldered on the controller board. The disk comes in versions with native access to 4 KB partitioning or emulation of 512-byte sectors, with a SATA or SAS interface. In the latter case, the option of end-to-end data encryption is also available.
Retail prices for the WD Ultrastar DC HC530 configured with a SATA port and legacy 512-byte markup emulation are in line with the advanced features and technologies of this device: from 27 rubles. in Russian online stores and $495 on Amazon.
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Assembling a collection of 14 TB hard drives for comparative testing was not easy, and we were never able to get a suitable device from a third manufacturer - Toshiba. But instead, we got a model of the next generation, 16 TB. Now all three hard drive companies offer drives of this size, but it was the Toshiba MG08 series that was the very first among them. The Japanese company's record is based on platters with roughly, if not exactly the same physical density as the 14TB BarraCuda Pro and Ultrastar hard drives, but for the first time, Toshiba was able to pack nine "pancakes" at once into a standard 3,5-inch case. Not without TDMR technology, which has become an indispensable condition for conquering new capacity frontiers. The Toshiba MG08 throughput in linear read/write operations should be on par with the WD Ultrastar DC HC530, but, oddly enough, the manufacturer does not disclose any details about the performance of the device.
But it is known that Toshiba also took measures to increase reliability and at the same time reduce the latency of write operations: the flash memory chip on board the MG08 in the event of a power failure allows you to save the data sent by the host controller for writing, but judging by the test results , also performs the function of the second level of cache memory after the DRAM buffer. However, this technology (Persistent Write Cache) appears only in the specifications of disks with 512-byte layout emulation, which is an additional source of danger during a power failure (and steals performance to some extent) due to the need to perform a read-modify-write operation every time. records of logical blocks that do not coincide with the boundaries of physical sectors. But the MG08 series also includes models with native access to 4-kilobyte sectors. Does this mean that the latter are completely deprived of flash memory, or they just removed the backup function from it, we do not know. But regardless of PWC, Toshiba MG08, and other drives of this company, uses Dynamic Cache algorithms, which, according to the manufacturer, optimally allocate buffer space between read and write operations. We also do not have any detailed information about them.
Other sources of increased fault tolerance in the design of the Toshiba MG08 are the spindle mounting on both sides and rotational vibration sensors. These drives are designed to write 550 TB of data per year, have a typical enterprise-grade 2,5 million hour MTBF, and a five-year warranty. Several different drive configurations are available for ordering with SATA or SAS interface and optional end-to-end encryption. We can't give you a price point, though: Toshiba's 16TB drive was introduced back in January, but it's still a rare beast in retail.
Toshiba MG08 16TB
Now that we've met the top three testers, let's take a look at the smaller hard drives we'll be comparing the new 14-16TB models to. One of them, the 10TB Exos X10, is a nearline drive containing seven magnetic platters in a sealed enclosure. And although since the usable capacity of the plate has grown from 1429 to 1750 GB or more, the speed of sequential access in hard drives should also increase, in this parameter the Exos X10 is practically not inferior to the same 14 TB BarraCuda Pro according to the specifications of both drives. Something clearly does not converge in the specifications of Seagate hard drives, but we have the opportunity to learn everything in practice.
In order to increase the speed of random access operations, the Exos series has an advanced AWC (Advanced Write Caching) write caching mechanism that reduces response time. Under AWC, writes are grouped in a DRAM buffer like any other hard drive, but the buffer retains a copy of the data after it has been flushed to the platter, and the contents of the mirrored buffer can be immediately read by the host controller. IN The 2,5-inch AWC form factor includes the next fastest stage - reserved areas on the platter surface where data from DRAM is written in sequential order (Media Cache), as well as a small amount of non-volatile memory to save data from the buffer during a power failure. But Exos X10 lacks flash memory, and maybe Media Cache along with it.
Compared to consumer desktop and NAS hard drives, Exos series drives have high MTBF (2,5 million hours) and design load (550 TB / year), the ability to operate in a server rack without a limit on the number of baskets, as well as a five-year service life. warranty service. The hard drive with the model number ST10000NM0016, which we got for testing, also belongs to Hyperscale modifications that have lower power consumption compared to other members of the Exos family, but are only available with a SATA interface and emulation of 512-byte sectors. In configurations with a SAS connector among Exos models, there are options with native access to 4-kilobyte sectors, as well as end-to-end full disk encryption.
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The Seagate IronWolf hard drive was recently featured in new representatives of this brand, along with a Seagate SSD for network storage. The 12 terabyte IronWolf model appears to be equipped with platters with the same physical marking density as the Exos X10, only there are one more of them. However, Seagate estimates the performance of its offspring in sequential read and write operations is much lower - only 210 MB / s. And there are no sophisticated technologies aimed at compensating for the high response latency inherent in magnetic storage devices here either.
But all IronWolf hard drives, starting with a volume of 4 TB, have borrowed a number of hardware features from the Exos series that contribute to increased fault tolerance. The block of magnetic plates of each hard drive is balanced in two planes, and rotational vibration sensors ensure stable operation in a rack storage system or a stand-alone NAS with up to eight drive cages. The IronWolf is rated for a moderate duty cycle with a design load of 180 TB/year and has a MTBF of 1 million hours. As a result, the warranty period for IronWolf is not as long as for more serious models in the Seagate catalog - three years.
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Under the S300 brand, the Japanese company Toshiba has released a series of drives for video surveillance systems - these hard drives are also dedicated to their own on the pages of 3DNews. By extending the ATA Streaming Command Set data transfer protocol, the older Toshiba S300 models guarantee simultaneous video recording from 64 surveillance cameras, but at their core they are typical drives for NAS and DAS with the ability to operate 24/7 and a decent MTBF: like IronWolf, it is 1 million hours, and the warranty period is the same three years. The S300's dual-sided spindle mounting and active rotational vibration dampening design features allow more than eight of these devices to be installed in a single rackmount or stand-alone NAS.
The S300 model, chosen for comparison with new products with a capacity of 14-16 TB, is based on the MD06ACA-V server disk hardware chassis and contains seven magnetic platters, and the device specifications indicate a random read / write speed of 248 MB / s typical for modern large-capacity HDDs . But of those tricks that are used in Toshiba server hard drives to reduce latency, the S300 has only the Dynamic Cache function.
Unlike all other test participants, S300 even with a dense stack of seven plates does without helium and is made in a standard ventilated case. It seems that this is the reason why the 10 TB model has the highest power consumption value in the summary table of specifications of the test participants, and this parameter, although important only for data center administrators, directly determines the temperature of the HDD. We will check the real power consumption of the S300 on our own, but for now we will take note of this item.
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Source: 3dnews.ru