WD Black SN750 NVMe SSD 1 TB Detailed Review

The WD SN750 is the third iteration of the WD Black lineup of the M.2 SSD. Last year, we saw the 2018 WD Black SSD that changed something for WD and made the drive an exciting drive. This is a significant improvement over the first generation of WD SSDs that could not distinguish themselves from hundreds of other SSDs on the market. This was primarily due to the new proprietary controller which demonstrated the vertical integration of WD. With the SN750, we should see another high-performer that they are stuck with the same proprietary controller and even the same 64-level 3D TLC NAND. We are probably seeing a modification of the controller with advanced firmware in this new SN750 package. One thing that sets SN750 apart is the huge EKWB heatsink that comes with it. There are different types available without heatsink.

WD Black SN750 NVMe SSD 1 TB Specification

WD did not share any controller specifications. By comparing the spec sheets side by side we can see that virtually all spaces are the same except for the reading and writing features. This indicates that most of the improvements to this SKU are in firmware. Rated Seq. Reading speed is improved by 70 MBps and rated Seq. Writing speed increased to 200 MBps. Randomly read and written IOPS statistics also show increasing improvement.

The 2018 WD Black was only available in the 250GB / 500GB / 1TB variant whereas the 2019 SN750 now also has the 2TB option. According to the rated specification, 1 TB SKU, which we also have, seems to be the best performer in the lot. Let’s take a look at the specifications of this particular SKU.

Construction and design

The first thing you notice about the WD Black SN750 is the Hitsink. The need for a heatsink has often been debated in analytics circles, and the answer lies in how and where SSDs are installed. Most users rarely achieve the threshold of thermal throttling if there is a lot of incidental airflow, if not then there is a very realistic possibility of SSD throttling. You may want to check the clearance of WD Black before installing it on your motherboard as it is quite a long heat sink. The SSD is 8.10mm long and has a Hitsink installed and also has that once it is installed, it will sit a little higher on the motherboard as there is some clearance at the bottom of the M.2 port.

As a result, if your M.2 slot sits just below the graphics card, it can exert some pressure if the graphics card sags into its slot. A graphics card without the fancy shroud should ideally not make any contact once installed but we have seen some graphics cards where a heatpipe from the assembly comes out slightly from the bottom of a heatpipe card. It intersects with the SSD installed space. In fact, motherboard manufacturers have already solved this problem by providing SSD heatsinks supported by separate mounts that prevent any pressure to be transferred to the SSD.

The heatsink is wrapped around the SSD as you can see in the image above. So you have not only added height but also a slight addition of width. Combining the two is actually problematic for specific motherboards. WD is working out a compatibility list on their website, highlighting which boards are compatible and which boards need to be removed before installing the heatsink.

Finally, the heat sink is a huge slab of aluminum with a V-shaped groove. While it is undoubtedly stylish and blends in with the aesthetics of most motherboard designs, it is not as effective as a proper fin-stack heatsink but it seems appropriate in the application scene.

Once you open the label, it cannot be separated from the built-in PCB 2018 WD Black SSD. It is a one sided PCB whose controller, NAND and RAM are the same. So nothing has changed with the WD SN750.

Overall, the WD Black SN750 keeps the configuration the same but has a new heatsink which seems to be a concern when paired with some motherboards.

Performance

You may be wondering if there is a difference in performance if the NAND chips are kept the same as the controller and the firmware is the main difference. You will be amazed at what can be achieved with just software / firmware tweaks. When we look at CrystalDiskMark, which is a very common and synthetic benchmark that shows the speed of raw reading and writing, you will not see a serious improvement. CrystalDiskMark can rarely bring the finesse of firmware improvements but we have it because it is popular. Performance numbers seem to be closer to the spec sheet, which is close to the 3470 MBps mark for reading speed and write speed to 2800 MBps. There is not much to explore here.

Moving on to analyzing driver performance post conditioning, we begin to see the difference between WD Black 2018 (SN700) and WD SN750.

Sequential reading performance
The WD SN750 has scored more than the WD Black SN700 at a significant interval of about 360 MBps in our Durable 128K Reed Test. This brings it closer to the Intel 900p and Corsair MP510, both of which are great performers in their own right. Samsung’s 970 EVO is comparable but it should be noted that our 970 EVO was a 512 GB SKU and not 1 TB SKU, all the other drives we test.

Performance of serial writing
Even in successive write performance tests we find the WD750 which shows an improvement of about 480 MBps which is quite large. It turns out that the firmware from WD is actually a good performer in all the most important parameters.

SSD performance is not just about pure reading speed or writing speed. All new controllers are able to easily handle synthetic loads that lead to metrics that do not indicate real-world performance. So we’re going to look at the latency timing for each operation across different row depths.