Why is M.2 NVMe SSD better than classic 2.5" SATA?

We also recommend reading"How to choose an SSD drive for a desktop PC and laptop?" and "We are building a powerful gaming PC with a monitor for $1500".

Not all M.2s are the same

It is worth starting, perhaps, with the fact that M.2 is a common name for several types of compact solid—state drives at once. They differ not only in size (4, 6 or 8 cm), but also in interface (SATA or PCIe). The cheapest M.2 SATA, for example Transcend MTS820 M.2 TS120GMTS820 120 GB , do not differ in speed from classic 2.5-inch SSDs. But the compact size allows you to install them in ultrabooks and nettops.

Fast M.2 NVMe drives work on the PCIe bus, and with different bandwidth. Previously, the PCIe 2.0 bus was used, whereas now it is 3.0 with the number of lines x2 or x4. Simpler models (PCIe Gen3 x2) are theoretically limited to 1600 Mbps, but in fact they are equipped with even slower flash memory (900 – 1200 Mbps).

Flagship SSDs thanks to the x4 bus are capable of speeds up to 3200 Mbps, but their price tag is downright "cosmic". Optimal, in our opinion, are the mid–price models with the x4 bus, the speed of which, of course, is not the flagship (1700 – 2000 MB / s), but still significantly higher than that of the x2 models. An example of this very "golden mean" is Transcend SSD110S TS128GMTE110S 128 GB .

Before buying an NVMe drive, we strongly advise you to make sure that your computer or laptop supports it exactly. So, old motherboards with an M.2 slot can be limited in speed by the PCIe 2.0 interface, and for example, the AMD Athlon 200GE processor, although it supports PCIe Gen3, but only the x2 bus. Most of the mid–price laptops (500 – 700 dollars) are generally compatible only with M.2 SATA drives.

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Transcend SSD110S TS512GMTE110S 512 GB 

Other popular SSDs Transcend

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from 2 577 ₴

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Configuration of the test bench

• processor AMD Ryzen 3 Raven Ridge 2200G BOX ;
• cooler Enermax ETS-T40F-RF ;
• graphics card — built-in Vega 3
• motherboard Biostar X370GT7 Ver. 5.x ;
• RAM Transcend JetRam DDR4 1x8Gb JM2400HLB-8G ;
• Transcend MTE110S 512GB Solid State Drive
• hard drive Seagate BarraCuda Compute ST2000DM008 2 TB 256/7200 Price from 2 299 up to 3 815 ₴;
• power supply unit Seasonic FOCUS PX FOCUS PX-650 Price from 8 159 up to 8 358 ₴;
• housing NZXT H500 red .

Speed testing

Measurements of the 512-gig version of Transcend MTE110S, like any other SSD under test, were carried out using the CrystalDiskMark and HD Tune Pro applications. The most important performance indicators of a solid — state drive are:

• sequential read and write speed — demonstrates how the disk handles with large files (the first line in the first screenshot of the CDM), and whether it has speed drawdowns after a certain amount of writing (typical for TLC and QLC flash memory, HDTP screenshot)
• the speed of reading and writing 4K blocks — shows how fast the disk processes the smallest files (the last line in the first screenshot of the CDM).
• IOPS — the speed of incoming and outgoing requests, inversely proportional to the delay (the third and fourth line in the second screenshot of the CDM).

And so, the sequential read speed of Transcend MTE110S in CDM was almost 1700 Mbps, and the sequential write speed was almost 1450 Mbps. This is slightly lower than the level stated by the manufacturer (probably the reason is not the fastest M.2 slot of our instance of the motherboard), but still higher than the theoretical maximum of PCIe Gen3 x2. The IOPS indicator is even more impressive — 240K, which is three to five times higher than the usual 2.5" SSD.

In turn, the HD Tune Pro benchmark allowed us to analyze the principle of operation of the virtual SLC caching of the SMI SM2263XT controller. Unlike Phison and Marvell solutions, which strictly limit the cache size (for example, 8 GB), SMI has a cache volume equal to a third of the free disk space. Thanks to this, it was possible to write about 150 GB of data to an initially empty 512-gig SSD without speed drawdowns. But even after the initial drop in speed, the disk still managed to partially restore high speed after short periods of time (as can be seen from the HD Tune Pro graph). Impressive, isn't it?

In the case of high-speed NVMe SSDs, it is also worth considering the possible overheating of the controller and the subsequent drop in speed due to its fault (and not TLC memory). But no such thing was noticed for the Transcend MTE110S: in an open stand, the disk did not heat up above 53 °C even without the cooling radiator of the motherboard. Emergency speed reset for other SSDs usually occurs after 75 – 80 °C.

The guaranteed rewriting resource of the 512-gig Transcend MTE110S is 150 TB. This means that for five years, an average of 80 GB of data can be recorded daily — a figure that is almost unattainable. And after this limit is exhausted, the disk will not stop working at all, but can only begin (and even then not necessarily immediately) to slowly "lose weight" in volume, alternately blocking the most worn-out memory cells. You can find out the remaining rewrite limit in the proprietary Transcend SSD Scope application.

Conclusions

So is it worth paying extra for a high-speed M.2 NVMe SSD, like Transcend MTE110S, instead of the usual 2.5" SATA? In the overwhelming majority of cases, yes. To build a top—end gaming PC with a total low-cost of $ 1000+ and a margin of performance for several years ahead — a must have. For upgrading a gaming laptop or ultrabook, if it is used not only for web surfing, but also for professional programs (Photoshop, Vegas, 3ds Max), it will also not be superfluous.

Of course, for the price of an NVMe disk with TLC memory (at least 3K rewriting cycles), you can buy a slow, but wear-resistant SATA MLC (10K cycles). But this is important only for a very limited range of tasks, in particular web servers and video surveillance systems that overwrite tens or even hundreds of gigabytes of data a day. Whereas for home or professional use, a much faster, albeit slightly less hardy M.2 NVMe TLC disk is better suited. Of course, there are also ultra-high-speed MLC SSDs, but their price is correspondingly ultra-high.