TRIM Performance:
While SSDs offer many benefits, there are some downsides to using flash memory. One of the biggest issues people run into is performance degradation. Over time, an SSD will run out of fresh blocks and will have to write over data the file system has marked as deleted. This procedure is very complicated and can slow an SSD's write speeds considerably.
To fix this problem, most manufacturers have added TRIM support to their SSDs. The TRIM command allows an operating system, such as Windows 10, to tell an SSD which data blocks are no longer in use. Using this information, the drive pro-actively erases these blocks and adds them to the free block pool.
To test the WD Black SN750's TRIM and garbage collection functions, I first put the drive in a "dirty" state. I used Iometer to fill the entire drive and then ran a random write test for 30 minutes. Looking at the screenshot below, you can see that the WD Black SN750's average read and write speeds dropped to 124.2 MB/s and 441.1 MB/s, respectively.
WD Black SN750 - Dirty
To see how well the WD Black SN750 could recover, I let the computer sit for about 30 minutes and then reran the test. The drive wasn't able to reach the factory fresh performance shown in our earlier tests. However, its average read speed climbed up to 323.6 MB/s.
WD Black SN750 - After TRIM
Unfortunately, the WD Black SN750 does not support the secure erase function so I was not able to wipe the drive with Parted Magic or even Western Digital's own SSD Dashboard software. Instead, I did a quick wipe and format from within Windows. After this, the WD Black SN750 was able to read at 1505.4 MB/s and write at 932.4 MB/s.
WD Black SN750 - Secure Erased
Final Thoughts:
Western Digital has knocked another one out of the park with its new WD Black SN750 SSD. Building off the success of the award-winning WD Black NVMe, this single-sided, M.2 form factor SSD is powered by Western Digital's own Spectrum controller and is available with up to 2TB of the company's 64-layer BiCS 3D TLC NAND flash. Combine this with an ultra-fast PCIe Gen3 x4 NVMe 1.3 interface and you have a drive that is capable of delivering the top-tier performance that gamers and enthusiasts are looking for. The 1TB version of the WD Black SN750 flew through our sequential transfer rate tests, reading at speeds as high as 3,498 MB/s and writing at more than 3,022 MB/s. The drive also did very well in our random write tests, producing more than 220,000 IOPS at low queue depths.
The WD Black SN750 is available now without the heatsink in 250GB, 500GB and 1TB capacities. Prices on Amazon.com currently range from $80 up to $230 for the 1TB version reviewed here. The 2TB version is expected to ship in the spring for about $500. The heatsink equipped models should also hit retailers at this time. However, there is no word yet on pricing.
Highs:
- Available in 250GB, 500GB, 1TB and 2TB capacities
- PCIe Gen3 x4 NVMe 1.3 interface
- Equipped with 64-layer BiCS3 3D TLC NAND
- Excellent sequential and random read and write speeds
- Small M.2 2280 form factor
- Large DRAM cache
- Available with or without EKWB-designed heatsink
- WD Black SSD Dashboard with "gaming mode"
- Reasonably priced
- 5 year warranty
Lows:
- Does not support hardware based encryption
