Write Test VS Read Test

A comparison of the two fastest NVME SSDs in the market today reveals a world of difference when comparing the actual write speeds that are achievable for the consumer. The difference between the two is the size of the SSD, the difference in the drive architecture, and the difference in the form of multi-level NVRAM. All three differences lead to the most important being the physical size of the drives. Larger, faster drives enable better write speeds, and it is here where the M.2 SanDisk SM Genie is able to win over the comparably sized and less expensive NVME SSD.

nvme ssd speed


To compare the write speeds of the two in a comparable configuration is nearly impossible, since the SSDs are all different. The obvious difference is the size of the devices, with the SM Genie SSD measuring approximately twice as big as the NVME SSD. This means that the drive is much larger than the traditional Firewire interface drive used in netbooks. To compare the SM Genie against the conventional Firewire interface drive, we would need to have an entire computer worked on in order to get the write speeds of the two to the same level. This is obviously not the case, and the gap between the two can be quite significant. The other difference that is most noticeable is in the architecture of the drives.


The conventional NVME SSD has an array of write commands going through the transistors in each cell, requiring the device to read from the host processor’s ROM and write the requisite data into the corresponding cells. The SM Genie on the other hand only requires a single address to instruct the SSD how to translate that single write command into an actual data write. In a write test scenario this can translate to a significant difference in the results. The time it takes for the NVME SSD to respond is less and the probability of inconsistencies in the results is increased greatly.


In the write test the two drives use the identical process to transfer 2 gigabytes of data. The difference lies mainly in the time it takes for the NVME SSD to read the required data and the time it takes for the SSD to write the required data. Assuming the usage scenario in which the computer is idle, then it should take approximately eight times as long to perform these tasks as it would if the computer is running under heavy load. Once the workload is added back on the computer the time taken to read the desired data reduces by a further 16 percent. This is the reason why many people believe that the performance of the NVME SSD is much better than the SSD based on performance alone.


There is another aspect to consider when looking at the differences between the two such as drive transfer speed. In the write test the difference is very minimal; however the read speed increases by only 0.3 percent. In all other aspects such as performance, power consumption, battery life, etc the difference is quite significant. It is thus safe to conclude that the performance of both the drives is very similar when it comes to the performance required for the application.


Both the drives are able to achieve their write speeds without any changes to the configurations and settings that are present in the OS. Once the workload is added back onto the system the speed increase becomes noticeable. The speed increase seen in the write test transfers the same amount of data in a shorter time, however the increase in read speed is much higher. Hence, it can be concluded that the differences in the performance of the two systems can be attributed to different reasons such as different workloads and different configuration of the OS.


Another interesting aspect of the evaluation is the time taken to read and write the random numbers. The data transfer speed can be clearly seen from the result sheet and the difference in this can be attributed to a relatively new feature known as Turbo Masking. The NVMe SSD has a faster read speed when compared to the Samsung SMART drives and the write speeds are almost equal. It is observed that this difference is also noticed with the different workloads; hence this may further suggest that Turbo Masking is responsible for the difference.


It can be concluded that both the drives are performing at similar levels, however Turbo Masking introduces some small tweaks into the system that greatly improve performance. The NVMe SSD has the advantage of faster performance at lower cost. It is important to look out for these kinds of features and advantages when purchasing an NVMe based SSD for your PC. The results often reveal the hidden performances that one may not be aware of