Flash drives, built on the four-bit memory QLC 3D NAND, gradually starting to gain more widespread. Although this memory still makes many users distrust, sooner or later it will become the predominant option used in bulk solid-state storage. And it will happen, obviously, at the most banal reason: due to the higher density of information storage QLC 3D NAND further reduces the cost of SSD drives, allowing in the near future to make available to the mass market, these models of SSD, capacity of which is measured not in gigabytes, but in terabytes.
We have had the opportunity to meet with one of the first SSD on the basis of the QLC 3D NAND, SATA drive Samsung 860 QVO. However, Samsung is not the only manufacturer that began mass production of four-bit memory, and decisions based on it. Own QLC 3D NAND also have Alliance Intel/Micron, and these manufacturers also use it in mass products for the consumer market. And started doing it even before they Samsung.
But to pay attention to QLC products to Intel and Micron have not even because they brought this technology to the mass market first. The fact that these manufacturers have to solve with the help of QLC 3D NAND several different tasks, making them QLC products differ from offers Samsung ideologically. While the Samsung 860 QVO is a simple consumer SATA SSD, which the South Korean manufacturer tried to minimize the price, the strategy of Intel and Micron proved more resourceful. They began to introduce QLC 3D NAND drives with the NVMe interface, not from the bottom, but with a higher price category. This approach is good because it allows to demonstrate the potential of four-bit memory on a bright and clear example, proving that QLC 3D NAND is not necessarily an option for the budget and slow drives with reduced resource. This memory may be appropriate for products of higher rank, which are exactly the QLC-new Intel SSD and Crucial 660p P1.
Along the way, Intel and Crucial SSD 660p P1 solve another task. With their help, the manufacturers want to claim their ambitions in the segment of inexpensive NVMe SSD, which is currently on the rise. Lately we have seen many attempts to bring the cost of high-speed drives with NVMe interface to the indicators of conventional SATA SSD. But they all were connected either with the transition to the unbuffered design, or using controllers with stripped-down functionality, which ultimately is not the best way affects productivity. QLC 3D NAND allows you to do NVMe SSD cheaper the other way, avoiding the obvious structural flaws on the side of the controller.
As a result, in the face of Intel and Crucial SSD 660p P1 we have a very interesting combination of price and performance options. Among NVMe drives they have almost the lowest price, which may well be compared with the cost of the popular SATA models, but promises quite good speed performance, significantly exceeding the specifications of SATA hard drives. It turns out that Intel and Crucial SSD 660p P1 downright begging to be a better alternative for the ageing SATA SSD.
However, if everything comes out so neatly in practice — or QLC 3D NAND still imposes on the performance and other consumer features NVMe SSD an indelible imprint? The answer to this question is the subject of this review, the protagonist of which will be Intel SSD 660p.
⇡#Specifications
The first thing that is of interest in the Intel SSD 660p is a brand QLC 3D NAND Intel authorship. The fact that this memory is slightly different from the already familiar to us QLC-memory, Samsung’s implementation, and this causes some features of the drive from Intel, such as its long, five-year warranty period, despite the common opinion about the extreme unreliability of QLC 3D NAND.
However, used in the Intel SSD 660p flash memory – this is the real QLC 3D NAND, each cell that can have sixteen logic States, thereby achieving the ability to store four bits of information and 33% increase in areal density of data compared to the TLC-flash. Manufactured by Intel, the crystals QLC 3D NAND have a 64-layer structure as the signature TLC 3D NAND second generation, but the capacity of these crystals is increased to 1 Tbit.
At the same time, Intel continues to rely on the design of the cell with vertical floating gate, while Samsung, Toshiba and Western Digital decided to use traps charge. Each approach has its pros and cons, but Intel believes the floating gate of a more appropriate scheme for QLC-memory, since in this case it achieves the best mutual insulation of the cells and prevents uncontrolled run-off charge. In other words, this approach allows Intel engineers to easily circumvent the main problem QLC-memory – low reliability of data storage in the off state.

That is why the company did not cut back the warranty period Intel SSD 660p, as if forgetting that the drive is built on a cheap four-bit memory. However, in the framework of the full five-year warranty manufacturer announces not too generous even for the average user, the resource, implying the possibility of daily overwrite only 10% of the total drive capacity. This means that the array of the flash memory the Intel SSD 660p per life time is allowed to overwrite only 200 times. And it’s really small, even for my Samsung QLC-drives series 860 QVO allows almost twice of write cycles (360), though it gives only a three-year warranty. Drives based on TLC memory from the point of view of official guarantees is allowed to overwrite on average over the lifetime of the order of 600 times.
Nevertheless, you need to understand that everything given in the last paragraph number is the only Declaration that may be far from reality. And to ensure that the reliability the Intel SSD 660p no special claims, in the preparation of this review, we have carefully studied the reviews on the popular foreign online sites. Indeed, despite the fact that this SSD is present in sale since August of last year, no complaints related to his premature failures or problems with data integrity, in reviews buyers not found. On the contrary, in most reviews customers praise 660p for great prices and the opportunity to save money.
Complain users at all otherwise – not too high a level of performance that is often lower than expected. But this is not surprising. QLC 3D NAND is slower than TLC memory, for obvious reason: the controller for digital processing of data read from the four-bit cell, we have to recognize twice as many different States, which, of course, is more complicated computational task. In addition, the effect and a low degree of parallelism of the array of flash memory assembled from QLC 3D NAND devices. The capacity of the crystals in this case is 1 TB, so the design of the drive of 512 GB, for example, involved only four devices, which is obviously insufficient for efficient parallelization of applications.
Base controller for the selected 660p also not flagship. Intel continues to work closely with the company Silicon Motion, and QLC-drive she prefers a dual-core chip SM2263, which is a stripped-down four-channel version of the controller SM2262 used in the popular Intel SSD 760p. For the simplified controller claimed about half the worst computing experience, it is not surprising that the stated performance Intel SSD 660p on the background level solutions 970 Samsung EVO looks doesn’t matter.
But do not forget that the Intel SSD 660p does and is not going to compete with an efficient NVMe models. It is rather a compromise solution, so the official specifications should not cause any surprise.
Manufacturer |
Intel |
Series |
SSD 660p |
Model number |
SSDPEKNW512G8 |
SSDPEKNW010T8 |
SSDPEKNW020T8 |
Form factor |
M. 2 2280 |
Interface |
PCI Express 3.0 x4 NVMe 1.3 |
Capacity, GB |
512 |
1024 |
2048 |
Configuration |
Flash memory: type, process technology, manufacturer |
Intel 64-layer 1-Tbit QLC 3D NAND |
Controller |
Silicon Motion SM2263 |
Buffer: type, volume |
DDR3L, 256 MB |
Performance |
Max. sustained sequential read, MB/s |
1500 |
1800 |
1800 |
Max. sustained sequential write speed, MB/s |
1000 |
1800 |
1800 |
Max. speed of random read (blocks 4 KB) IOPS |
90 000 |
150 000 |
220 000 |
Max. speed random write (blocks 4 KB) IOPS |
220 000 |
220 000 |
220 000 |
Physical characteristics |
Power consumption: inaction/read-write, W |
0,04/4,0 |
MTBF (mean time between failures), million h |
1,6 |
Resource record, TB |
100 |
200 |
400 |
Dimensions: Ghvhg, mm |
80,15 × 22,15 × 2,38 |
Weight, g |
10 |
Warranty period, years |
5 |
You can even think, if formal specifications do not take into account technology SLC-cache. But this is not so, the technology of rapid entry, the drive is there, but the Intel SSD 660p do not hit records and in any type of operation does not fill the entire bandwidth provided by PCI Express 3.0 x4. However, for the NVMe drive, the unit cost of which is close to $0.17 per Gigabyte, it is quite normal. Intel SSD 660p is not inferior to the characteristics of the most inexpensive NVMe SSD class A1000 Kingston or Transcend SSD 110s.
As for SLC-caching, it is a subject of special pride of developers of 660p. The drive on the base of QLC-memory write speed which is very low, quality this technology means a lot. Judge for yourself: directly in the 3D NAND array QLC polterabayta version of Intel SSD 660p writes data only at a speed of about 55-60 MB/s, and it’s two to three times below the performance of the linear record have a modern mechanical HDD. For this reason, the QLC drive without SLC cache would be completely pointless device, and the size of this cache should be possible as much as possible to the user is not faced with the real speed QLC 3D NAND.
For this reason, the Intel SSD 660p switched to the dynamic circuit SLC-caching, when most of the array of flash memory works in a fast SLC mode, and the translation of four-bit cells in QLC mode occurs only as needed, when entries in a single bit mode in the array of flash memory not enough space. Generally speaking, such an approach is typical for almost all drives on the controllers Silicon Motion, but Intel is still in all of their products use a static SLC cache.
As a result, the linear speed of continuous recording on a clean Intel SSD 660p capacity of 512 GB as follows:
In SLC mode at 660p Intel SSD 512 GB can be translated approximately 50% of the array of flash memory. This allows you to record to the drive in fast mode up to 70 GB. But even in this case performance of the linear record is limited to the value of 900-950 MB/s, not to mention the fact that after filling the cache when the record starts to be produced in the main memory array in chetyrehbalnoy mode, performance is reduced to a very miserable performance. However, despite the fact that Intel SSD 660p – quite slow by the standards of the SSD NVMe models, in most cases, it is still obviously faster SATA-drives.
The algorithms of implementation of SLC-caching from the Intel SSD 660p there are three interesting features. First, the SLC cache, this drive is the static part by volume of 6 GB for every 512 GB capacity SSD. It allows you to store high speed recording even if the volume of SSD almost to the eyeballs busy user files and deploy capacious dynamic cache is not possible.
Secondly, the contents of the SLC cache is transferred to the QLC-memory not immediately, but only during a relatively long downtime of the drive. On the one hand, it slightly reduces the effectiveness of the cache, which may be filled, but with another – allows to speed up and the read operation, if data access to occur immediately after recording them. Especially effective this tactic manifests itself in the benchmarks that measure the speed of reading immediately after the test file.
In addition, Intel came up with something very special – the developers decided to give some control over SLC cache in the user’s hand. Proprietary utility SSD Toolbox to 660p can send the controller a command for the forcible transfer of all information from the SLC cache to the QLC-memory. And this, obviously, allows you to pre-provision storage to record large amounts of data.
⇡#Appearance and internal structure
Lineup of solid state drives Intel has a clear structure. 500-series are SATA drives, 700 series includes NVMe SSD with good performance and 600-series is somewhere in the middle. On the one hand, such drives have an interface NVMe, and on the other provide a low cost and not putting records products. That Intel SSD 660p – a product not of premium level. While the Intel SSD 760p is made on black PCB and has a black label SSD 660p with a green PCB and a plain white sticker is more like a solution for OEM collectors, not enthusiasts.
However, for an inexpensive SSD NVMe appearance does not matter much, much more interesting to look at what components assembled 660p. For testing, we took a version with 512GB. Without a label it is shown in the photo below.
Intel SSD 660p made in the traditional form factor M. 2 2280, and in his thin, one-sided version. It clearly shows the advantage of large crystals QLC 3D NAND. Stacking 16 of these crystals flash memory you can obtain IC total volume up to 2 TB, so in theory the reality can be unilateral 660p with 8TB. But while Intel is such a large your SSD is not produced, and therefore the costs of the chips with only two or four crystals 64 layer 3D NAND QLC inside. For example, in the Intel SSD 512 GB 660p uses a chip with two crystals on the Board so photographed it is possible to observe two chip flash memory. Next to them are reserved, loose pads for another pair of chips – they are only required in versions of the SSD capacity of 2 TB.

SM2263 controller that controls a four channel array of the flash memory is recognizable by Nickel plated cap that improves heat sink. Please note the dimensions of this chip compared to the eight SM2262 it was significantly less that clearly alludes to his stripped-down performance.
This is also indicated by the chip DDR3L SDRAM installed on the Intel SSD 660p. Typically in dram, memory is stored a copy of the table of address translation, which requires the volume rate of 1 MB DRAM 1 GB flash memory. However, 660p any tanks the size of the DRAM buffer is 256 MB. Consequently, the translation table is buffered in fast memory not as a whole, and this can limit the drive performance when accessing large data volumes.
It is worth noting that was mentioned in the beginning of the article storage Crucial P1 uses exactly the same circuitry as the Intel SSD 660p. But the manufacturer did not skimp on the amount of DRAM buffer and also did not set a goal to place all the chips QLC 3D NAND on one side of the Board. Therefore, the decision of the ITC differs from the Intel SSD 660p design and obviously has some features in profile performance. Although the Intel drives SSD Crucial 660p and P1 should be similar in performance.
⇡#Software
Intel traditionally supplies your drives and quite functional utility SSD Toolbox, which is compatible with Intel SSD 660p. In features she is largely similar to other similar programs. This utility not only allows you to get detailed information about the status of your drive, but has a whole set of additional tools for tuning and optimizing.
For example, it can be sent to the drive package TRIM commands in interface SSD Toolbox, this feature is called SSD Optimizer. With this action service is a utility that can perform not only disposable, but also offline, according to a schedule. In addition, Intel has provided another opportunity for optimization software – forced clear the contents of the SLC cache drive. This is a unique opportunity Intel SSD Toolbox, no service utilities other manufacturers drives, so do not know how.
In the SSD Toolbox there is a possibility of a diagnostic scan, during which you can check the status and operability of the flash memory. The scan runs as fast and full mode – the difference is that affect whether the verification of the entire array of flash memory or only some part of it.
Also use the SSD Toolbox to check the relevance used by the drive firmware and initiate the Secure Erase operation.
Another trademark feature antalovsky service utilities – System Tuner. With it, you can see the critical settings related to the disk subsystem includes the operating system, as well as to obtain recommendations for changes.