Updated 23.02.2021

Differences in SSDs

 

You will surely have noticed it when looking for an SSD. There are significant price differences between the various models, even with the same manufacturer and the same storage capacity. These price differences are justified because there are enormous differences in the quality of SSDs. The quality affects both the speed and the durability of the SSD.

Cheap SSDs often have no DRAM cache anymore and therefore do not perform much better than a fast HDD. The more expensive the SSD, the better the built-in controller is. This is an important component of an SSD, to which little attention is paid. The controller controls the read and write functions and ensures that the correct data is found as quickly as possible.

Memory types for SSDs

Another very important feature of an SSD is the type of memory used. An SSD consists of countless tiny memory cells. Depending on the type of memory, different numbers of bits can be stored in each cell. The more bits per cell are being stored the less durable an SSD is. However, SSDs with more bits per cell are cheaper to produce. Therefore, an optimal compromise between price and memory type must be found.

SSDs for the PrimeMini

For these reasons, we only use Samsung EVO 860 or, on request, Samsung 970 PRO SSDs in the PrimeMinis. The Samsung EVO 860/870 is a TLC (Tripple-Level Cell) SSD with 3 bits per cell and the Samsung 970 PRO an SSD with 2 bits per cell (The Samsung 980 PRO is TLC!). These SSDs are not the cheapest on the market. But the extra cost is worth it.

It is not always easy to find out which type of memory the manufacturers use for a particular SSD. In principle, the following naming convention applies:

• SLC = 1 Bit per cell
• MLC = 2 Bits per cell
• TLC = 3 Bits per cell
• QLC = 4 Bits per cell

But for example, the Samsung EVO 860/870 is marketed by the manufacturer as an MLC-SSD. Consequently, it would have to contain 2 bits per cell. MLC stands for “Multi-Level Cell”. So theoretically all SSDs with more than 1 bit per cell are MLC-SSDs. In practice, however, MLC actually only stands for SSDs with 2 bits per cell. Samsung’s marketing department has come up with a nifty solution here, naming MLC (3-bit) as the memory technology for the Samsung EVO 860/870. In other words, a TLC-SSD. It is the same with SSDs from competing manufacturers, MLC is not always found when MLC is specified.

The lifespan of an SSD

The Samsung EVO 860/870 SSD in particular still offers the optimum mix of performance, quality and price for the PrimeMini. The lifespan of an SSD is crucial for use in a Mini-PC and especially in a Mini-Server. It is not unlimited, because the individual cells cannot be rewritten as often as you want. This lifetime or rewritability is indicated with the TBW, which stands for “Terabytes Written”. The number thus indicates how many terabytes can be written until the SSD has reached its theoretical maximum rewritability. With the Samsung EVO 860/870, however, we are on the absolutely safe side here. Quite in contrast to cheap SSDs. Even if the PrimeMini is used as a server or PC much longer than the 5 years included in the warranty.