Cheap ssd: all the information completa complete guide】

It is very usual that when buying one or more cheap SSDs we ask ourselves the following questions: Is this cheap SSD that I am going to buy worth? Is there really a noticeable difference with the more expensive models? Don't worry, in this article we are going to cover all the information about cheap SSDs and how manufacturers reduce their cost.

We have seen in recent years how the prices of SSDs have dropped dramatically, being able to buy a 500GB solid state drive for only € 60, or the 250GB version for € 40, this leaves without any excuse the idea of ​​not opting for one when mounting a PC.

To know why an SSD is cheap, you have to explain what elements they are made of and how to manage them. A solid state drive (SSD) is basically made up of the NAND memory , the DRAM, and the memory controller. Throughout this article we will see the importance of each one.

Index of contents

NAND memory and its types

NAND flash memory is a type of non-volatile storage technology that does not require power to retain data. These NAND logic gate based memories work slightly differently: they use an injection tunnel for writing and a 'drop' tunnel for erasure. NAND-based memories have, in addition to the obvious basis in other types of doors, a much lower cost, about ten times more resistant to operations.

There are four main types of NAND memory:

• SLC (single-level cell): It is the first to reach the market and was the main form of storage for several years. Because (as the name implies), it only stores a single bit of data per cell, it is extremely fast and long lasting. It is not very dense in terms of the amount of data it can store, which makes it very expensive. At this point, beyond extremely expensive business units and use as small amounts of fast cache, SLC has been replaced by new and denser types of flash storage technology like the ones mentioned below. MLC (multi-level cell): This type of memory stores multiple bits of data in a single cell. For years it was the type of storage chosen for its ability to store more data at a lower price, despite being slower by comparison. To avoid the speed problem, many of these drives have a small amount of faster SLC cache that acts as a write buffer. Today, removing some high-end models (where MLC memory makes sense when dealing with large amounts of files) has been replaced by the next step in TLC NAND storage technology. TLC (Triple Cell Level) - Still very common on current SSDs. While TLC is even slower than MLC, as the name implies, it stores 3 bits per cell. It is more data dense, allowing for more spacious and affordable units. Most TLC memories (except for some of the cheaper models) also employ some form of caching technology, because TLC alone without a buffer is not significantly faster than a hard drive.

For regular users who run normal day-to-day applications (browsers, Telegram, Word, etc.) with their respective operating systems, this is not a problem, since the drive does not usually saturate the cache faster. But professional and more demanding users who often work with massive files may want to invest in an MLC-based disk to avoid slowdowns and drops in reading and writing when moving large amounts of data.

• QLC (Quadruple Cell Level): It is emerging as the next stage in the evolution of solid state storage. And as the name implies, it stores four bits per cell, leading to cheaper and more spacious units thanks to an increase in density, albeit a much shorter lifespan. This type of memory together with the TLC are the ones used by the cheapest SSDs on the market, such as the Intel 600p, the Crucial P1, Samsung 860 QVO, etc.

It must be emphasized that all these memories are of the 2D flash type, that as their name indicates, is flat, all the cells that are capable of storing data are located next to each other. With 2D NAND flash, the capacity of flash memory is determined by how many cells can fit on a card, as well as how many bits of data can be stored in those cells.

With the space limitations of 2D NAND memories, 3D NAND emerged, this technology allows cells to be stacked on top of each other so that storage can be increased considerably. These layers dramatically increase storage capacity without the need to shrink cells. Stacking them actually allows each cell to be larger, increasing storage and reliability.

Each manufacturer uses its own 3D NAND technology, it was developed by Micron and Intel, V-NAND and Z-NAND created by Samsung, Super MLC 3D NAND is from Transcend, BiCS 3D Flash is from Toshiba, etc.

DRAM

At this point you will ask yourself, Why does my SSD need DRAM? What does it bring you? Well, every time the operating system requires data from the drive, it asks for it by locating the blocks. At that time, the solid state drive has to search for such data and send it to the operating system. It seems like a simple task, but even if it is an SSD, this data has to be searched physically. For this reason, our unit has saved (and constantly updated) a "map" with the location and content of all blocks. So when requesting something from the album, it knows almost immediately where it is. With this we avoid that the NAND memory wears out a lot less and we obtain a better performance.

DRAMless SSDs are fine for their intended purpose, making them cheaper for a user who is not going to make extreme use of their drive. Not having DRAM means that the PCB where all the components are mounted is less complex and in turn cheaper, this does not indicate that it has less resistance, as we mentioned before, the DRAM is only intended for mapping tables, not for caching of writing.

Cheap SSD Memory Controller

Think of the memory controller as the processor of our SSD. It manages all reads and writes and performs other key performance and maintenance tasks for the unit. It may be interesting to delve into different specific driver types and specifications. But for most users, it's enough to know that, like computers, "more cores are better for higher-performance, higher-capacity drives."

Manufacturers in some cases use older drivers (in the case of Chinese SSDs) to cut costs, such as the SandForce SF-2000 series driver. In other cases like Crucial's, they usually develop controllers that use DRAM-free architectures, instead the mapping is stored and executed directly in NAND memory, as is the case with the Silicon Motion SM2258XT.

Durability and guarantee

These are two areas in which the user normally has more interest. All flash memories have a limited lifespan, which means that after writing a certain storage cell a certain number of times, it will stop containing data and die. Manufacturers often list the nominal resistance of a unit in written total terabytes (TBW) or years.

In general, unless you want your SSD to mount a server or some other scenario where it's being written almost constantly, all drives today are rated strong enough to run for at least 3-5 years.

Obviously, as we have previously commented, a unit with QLC memory will have less durability than one with MLC, that added to its great fall in sequential readings, becoming worse than an HDD, is still not recommended to this day.

Conclusions about Cheap SSDs

At this point, answering the question , is a cheap SSD worth it? Well it depends on several factors, mainly your budget, many times we have a certain budget that does not allow us to acquire a better unit, but sometimes the difference between an SSD with TLC memories and without DRAM with another with TLC memories 3DNAND with DRAM is around of about € 10, for that small difference it is highly recommended to buy the top model such as the Crucial MX500, Samsung 860 EVO, etc. Another factor is the use that we are going to give it, if the only thing you are looking for is an SSD to lighten your operating system and install two or three games, because cheap models such as the Crucial BX500, Toshiba TR200, Western Digital Blue are perfect for you., etc.

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So far our article on cheap SSDs, hopefully it has served to clarify this issue, anyway, any questions you can leave in the comments.