A A measure of how well an SSD performs under typical consumer workloads. Samsung 850 Pro ~= 100%.
Measuring SSD performance is not for the faint-hearted. There are a plethora of speed readings available. A disproportionate emphasis can easily be placed on technical readings which don't translate into improved performance for typical users. The effective speed index is a measure of how well an SSD performs under typical consumer workloads: 50% sequential with an emphasis on lower queue depth performance. The details of the calculation are explained below.

Drive performance is broken into the below six categories: The real world speed index weights the above factors in the following proportions:
  • SeqR=25%
  • SeqW=25%
  • 4kR=20%
  • 4kW=20%
  • 4k64R=5%
  • 4k64W=5%
These weights were chosen because the majority of consumer IO (approx 50%) is sequential and the least common type of IO is deep queue depth. Consumer workloads rarely go beyond a queue depth of 4.

For comparison purposes here are the popular AS-SSD total score formula (approximate) weights:
  • SeqR=5%
  • SeqW=6%
  • 4kR=6%
  • 4kW=9%
  • 4k64R=46%
  • 4k64W=28%
There is a heavy bias (74%) on deep queue depth performance, something typical consumers are unlikely to benefit from. The AS-SSD benchmark total score is a far better gauge for server rather than consumer workloads.

 

See a current list of SSDs sorted by effective speed here.

The Best.
CPUGPUSSD
Intel Core i7-7700K $310Nvidia GTX 1070 $370Samsung 850 Evo 250GB $94
AMD Ryzen 7 1700 $325AMD RX 480 $193Samsung 850 Pro 256GB $138
Intel Core i5-7600K $215Nvidia GTX 1060-6GB $235Samsung 850 Evo 500GB $160
HDDRAMUSB
Seagate Barracuda 1TB (2016) $50Corsair Vengeance LPX DDR4 3000 C15 2x8GB $110SanDisk Extreme 64GB $34
Seagate Barracuda 3TB (2016) $90G.SKILL Trident Z DDR4 3200 C14 4x16GB $650SanDisk Extreme 32GB $22
Seagate Barracuda 7200.14 1TB $50Corsair Vengeance LPX DDR4 3200 C16 2x8GB $130SanDisk Ultra Fit 32GB $9
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