The Samsung PM981 SSD Review (512GB, 1TB): Next Generation Controller And 3D NAND

AnandTech Storage Bench - The Destroyer

The Destroyer is an extremely long test replicating the access patterns of very IO-intensive desktop usage. A detailed breakdown can be found in this article. Like real-world usage, the drives do get the occasional break that allows for some background garbage collection and flushing caches, but those idle times are limited to 25ms so that it doesn't take all week to run the test. These AnandTech Storage Bench (ATSB) tests do not involve running the actual applications that generated the workloads, so the scores are relatively insensitive to changes in CPU performance and RAM from our new testbed, but the jump to a newer version of Windows and the newer storage drivers can have an impact.

We quantify performance on this test by reporting the drive's average data throughput, the average latency of the I/O operations, and the total energy used by the drive over the course of the test.

The average data rate of the 1TB Samsung PM981 on The Destroyer is comparable to the 960 EVO 1TB and well ahead of any competing TLC-based drives like the Toshiba XG5. The 512GB PM981 is slower by a typical amount, and still faster than any of the non-Samsung drives of that size.

The 1TB PM981 shows a substantial improvement over the average and 99th percentile latency scores of the 960 EVO, putting it close to the 960 PRO. The 512GB PM981 isn't as impressive, with latency scores that fall behind most MLC-based NVMe SSDs.

The 1TB PM981 sets a new record (among flash-based SSDs) for average read latency on The Destroyer, shaving a few microseconds off the 960 PRO's performance. The average write latency can't quite keep up with the MLC-based 960 PRO that doesn't use SLC write caching. The smaller 512GB PM981 is competitive with most similarly-sized MLC-based drives, but slower than Samsung's 960 PRO.

Samsung's 99th percentile read latency is nothing special, though the PM981 does offer clear improvement over the 960 EVO. The 99th percentile write latency of the 1TB PM981 is excellent and far better than the 1TB 960 EVO. The 512GB PM981 is clearly the fastest TLC-based drive of that size that we've tested, but it doesn't quite match the 99th percentile latency scores of the MLC-based competition.