IOMeter v2006.07.27 – IOps
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.
Meanwhile Intel has discontinued to work on Iometer and it was given to the Open Source Development Lab (OSDL). In November 2001, a project was registered at SourceForge.net and an initial drop was provided. Since the relaunch in February 2003, the project is driven by an international group of individuals who are continuesly improving, porting and extend the product.
Light desktop usage sees QD figures between 1 and 4. Heavy / power user loads run at 8 and higher. Most SSD's are not capable of effectively handling anything higher than QD=32, which explains the plateaus.
Regarding why we use this test as opposed to single-tasker tests like 4KB random reads or 4KB random writes, well, computers are just not single taskers. Writes take place at the same time as reads. We call this mixed-mode testing, and while a given SSD comes with side-of-box specs that boast what it can do while being a uni-tasker, the tests above tend to paint a very different picture.
With that covered, lets take a look at where the 840 Pro sits on the field. First you'll notice that all Samsung units (blue, orange, and red lines) do extremely well, especially in the 1-8 range, which is where any consumer or even power user's OS sits the vast majority of the time. This is a testament to extremely low latency of the pair of 830s and the 840 Pro. While the 840 Pro is capable of higher read and write IOPS, this is mostly a mixed mode test, and when doing both at the same time, the 840 Pro remains mostly on-par with the 830. That similarity promptly ends once you take a look at the Web Server test results. In this read-only workload, the 840 Pro climbs above everything else, even doing so at much higher queue depths. This ~20% gain over the 830 is consistent with the increase in speeds stated by the product specs.