Random Performance – Iometer (IOPS/latency), YAPT (random)
We are trying something different here. Folks tend to not like to click through pages and pages of benchmarks, so I'm going to weed out those that show little to no delta across different units (PCMark). I'm also going to group results performance trait tested. Here are the random access results:
Iometer is an I/O subsystem measurement and characterization tool for single and clustered systems. It was originally developed by the Intel Corporation and announced at the Intel Developers Forum (IDF) on February 17, 1998 – since then it got wide spread within the industry. Intel later discontinued work on Iometer and passed it onto the Open Source Development Lab (OSDL). In November 2001, code was dropped on SourceForge.net. Since the relaunch in February 2003, the project is driven by an international group of individuals who are continuously improving, porting and extending the product.
* We will be discontinuing our File and Web Server tests for client SSD tests after this review, as they employ legacy workloads that are 16 years old (yes, in the year 2000) and are simply no longer representative of modern technology.
Iometer – IOPS
The 2TB EVO had an issue we noted in our original review, and while it's been a year since we communicated additional details to Samsung, the issue remains. Fortunately that same issue is no longer present with the 4TB model (and is now expected to be fixed on the 2TB at some point). The 2TB's issue was specific to IOPS performance not fully recovering after the drive was TRIMmed, for those curious.
Iometer – Average Transaction Time
For SSD reviews, HDD results are removed as they throw the scale too far to tell any meaningful difference in the results. Queue depth has been reduced to 8 to further clarify the results (especially as typical consumer workloads rarely exceed QD=8). Some notes for interpreting results:
- Times measured at QD=1 can double as a value of seek time (in HDD terms, that is).
- A 'flatter' line means that drive will scale better and ramp up its IOPS when hit with multiple requests simultaneously, especially if that line falls lower than competing units.
The above latencies are average figures. If you want far greater detail on this data, simply flip to the next page!
YAPT (yet another performance test) is a benchmark recommended by a pair of drive manufacturers and was incredibly difficult to locate as it hasn't been updated or used in quite some time. That doesn't make it irrelevant by any means though, as the benchmark is quite useful. It creates a test file of about 100 MB in size and runs both random and sequential read and write tests with it while changing the data I/O size in the process. The misaligned nature of this test exposes the read-modify-write performance of SSDs and Advanced Format HDDs.
YAPT is a 'misaligned' test, in that it does not adhere to 4k boundaries. Many modern drives don't agree with it very well at all, as you can see above. Samsung does better than most, and the dip seen in the 2TB model is happily resolved with the 4TB capacity.