Samsung 840 EVO SSD Review – Samsung Caches In On Value and Performance


ATTO Disk Benchmark is perhaps one of the oldest benchmarks going and is definitely the main staple for manufacturer performance specifications. ATTO uses RAW or compressible data and, for our benchmarks, we use a set length of 256mb and test both the read and write performance of various transfer sizes ranging from 0.5 to 8192kb. Manufacturers prefer this method of testing as it deals with raw (compressible) data rather than random (includes incompressible data) which, although more realistic, results in lower performance results.

Samsung 840 EVO 1TB SSD ATTO

ATTO high results of 555MB/s read and 535MB/s write are excellent considering that we are conducting first tests of a new NAND flash memory footprint and it is triple level cell.  Our ATTO results in both standard system, and optimized were identical, negating the necessity of posting both results.


Crystal Disk Benchmark is used to measure read and write performance through sampling of raw (0/1 Fill/compressible) or random data which is, for the most part, incompressible. In the Samsung 840 EVO SSD, performance results are very similar whether we test with compressible or incompressible data and, for this reason, results are displayed utilizing incompressible data.  Our results reflect standard testing on the left while those on the right are the result of CPU ‘C’ State optimization as described in The SSD Optimization Guide:

Samsung 840 EVO 1TB SSD CDMCPU Optimized Samsung 840 EVO 1TB SSD CDMThe optimized PC (right) clearly reflects an obvious performance boost with respect to low 4K random write performance.  Low 4K random write performance has been traditionally the Achilles heel in SSD progression as we have seen massive speed improvements at all other levels of disk access, yet the 4K read and writes remain right around that 100MB/s mark.


Up until recently, AS SSD was the only benchmark created specifically for SSD testing and it uses incompressible data. AS SSD, for the most part, gives us the ‘worst case scenario’ in SSD transfer speeds because of its use of incompressible data and many enthusiasts like to AS SSD for their needs. Once again, we will display the standard system on the left with optimized on the right:

Samsung 840 EVO 1TB SSD AS SSD BenchCPU Optimized Samsung 840 EVO 1TB SSD AS SSD BenchTaking a look at AS SSD IOPS as well, both SSDs display very impressive performance, regardless of whether it is a standard system or one that has been optimized:

Samsung 840 EVO 1TB SSD AS SSD IOPSCPU Optimized Samsung 840 EVO 1TB SSD AS SSD IOPSIOPS results of just under 100K seem to be the standard these days. Regardless, the Samsung EVO 840 provides some incredible results on the AS SSD Copy Benchmark:

Samsung 840 EVO 1TB SSD AS SSD Copy BenchmarkCPU Optimized Samsung 840 EVO 1TB SSD AS SSD Copy BenchmarkIt’s not often that we ever see +400MB/s speeds in the AS SSD Copy Bench