Random and Sequential Read/Write
We use Anvil's Storage Utilities 1.0.51 to measure random and sequential ref and write speeds. The synthetic benchmark integrated into this software suite provides a great overview of the products by experimentally checking out a wide variety of speed characteristics of the tested SSD.
The results you see here refer to the FOB (fresh out-of-box) non-degraded SSD performance. Moreover, we use incompressible data, which is formally the least favorable scenario for the LSI SF-2281 controller that employs on-the-fly data compression. Our tests show, however, that in today’s world when the data may only be partially compressed and the utilized flash memory has high-speed synchronous interface, the compression algorithms do not have a big effect on the real-life performance of SSDs with SandForce controllers. Therefore, we gave up the idea of testing SandForce-based SSDs with compressible data: These results would be exclusively artificial in nature and wouldn’t have any practical value for us today.
As promised by Samsung, the new 840 Pro claims to be the fastest desktop SSD available today. We can see that in our synthetic benchmarks. Its read speed is unrivalled at most popular types of operations, being only inferior to the read speed of the Plextor M5 Pro when the request queue is very long. The Samsung 840 Pro is good at writing as well, but its result is rather average when it comes to random-address writing with a small request queue.
The basic Samsung 840 is slower than its senior cousin. It is good at sequential reading and at reading large data blocks, but the high latency of its TLC NAND flash lets it down at writing and at processing 4KB data blocks. That said, the Samsung 840 does offer rather good performance for its low price. It is no worse than its predecessor Samsung 830 and can compete with such popular products as OCZ Vertex 4, Plextor M5S and Corsair Neutron. Samsung engineers seem to have made up for the high latency of TLC NAND flash in some way or another, so this SSD doesn’t look like an outsider among products with MLC NAND flash.