TEST SETUP AND METHODOLOGY
In testing all enterprise drives we focus on long term stability. In doing so, we stress products not only to their maximum rates, but also with workloads suited to enterprise environments. We use many off-the-shelf tests to determine performance, but we also have specialized tests to explore specific behaviors we encounter. With enterprise drives, you will see that we do not focus on many consumer level use-cases.
When testing SSDs, the drive is purged and then preconditioned into a steady state before capturing its performance results. We also disable all write caching on the DUT when possible, this ensures consistent results that are complaint with SNIA standards. Our hope is that we present tangible results that provide relevant information to the buying public.
|PC CHASSIS:||Thermaltake Urban T81|
|MOTHERBOARD:||ASRock X99 WS-E|
|CPU:||Intel Xeon E5-2690 v3|
|CPU COOLER:||Thermaltake Water 3.0 Ultimate|
|POWER SUPPLY:||Thermaltake Toughpower 1500W Gold|
|GRAPHICS:||MSI GT 720 |
|SYSTEM COOLING:||be quiet! Silent Wings 2|
|MEMORY:||Kingston ValueRAM DDR4 2400MHz ECC 64GB|
|STORAGE:||Crucial MX200 500GB|
|OS:||Windows Server 2012 R2|
This Test Bench build was the result of some great relationships and purchase; our appreciation goes to those who jumped in specifically to help the cause. Key contributors to this build are our friends at ASRock for the motherboard and CPU, be quiet! for the cooling fans, and Thermaltake for the case. We have detailed all components in the table below and they are all linked should you wish to make a duplicate of our system as so many seem to do, or check out the price of any single component. As always, we appreciate your support in any purchase through our links!
The Storage Networking Industry Association has an entire industry accepted performance test specification for solid state storage devices. Some of the tests are complicated to perform, but they allow us to look at some important performance metrics in a standard, objective way.
SNIA’s Performance Test Specification (PTS) includes IOPS testing, but it is much more comprehensive than just running 4KB writes with Iometer. SNIA testing is more like a marathon than a sprint. In total, there are 25 rounds of tests, each lasting 56 minutes. Each round consists of 8 different block sizes (512 bytes through 1MB) and 7 different access patterns (100% reads to 100% writes). After 25 rounds are finished (just a bit longer than 23 hours), we record the average performance of 4 rounds after we enter steady state.
- Purge: Secure Erase, Format Unit, or vender specific
- Preconditioning: 2x capacity fill with 128K sequential writes
- Each round is composed of .5K, 4K, 8K, 16K, 32K, 64K, 128K, and 1MB accesses
- Each access size is run at 100%, 95%, 65%, 50%, 35%, 5%, and 0% Read/Write Mixes, each for one minute.
- The test is composed of 25 rounds (one round takes 56 minutes, 25 rounds = 1,400 minutes)
Unlike our other performance tests, the SNIA tests only last for a relatively short period of time each (1 minute), but they cover many more access patterns and transfer sizes. All tests were done at a QD of 32. The HK4E achieved 93K IOPS in 100% read performance at 4KB, which is well over the 75K rating. In terms of writes, yet again it surpassed its rating and achieved 43K IOPS. Also, during the 4KB 65%/35% read/write portion of the test the drive averaged 63K IOPS, which yet again surpasses its manufacturers rating of 50K IOPS.
To specifically measure latency, we use a series of 512b, 4K, and 8K measurements. At each block size, latency is measured for 100% read, 65% read/35% write, and 100% write/0% read mixes.
The HK4E’s latency results are much better than the HK4R’s. At a QD of 32 the average latency results under 1ms except for during 100% 512kB and 8KB writes. For 100% read it averaged 0.2ms at 0.5KB, 0.343ms at 4KB, and 0.564ms at 8KB. 65% read results averaged 0.407ms at 0.5KB, 0.490ms at 4KB, and 0.930ms at 8KB. Finally, the HK4E averaged 1.036ms at 0.5KB, 0.734ms at 4KB, and 1.406ms at 8KB.
Moving onto the HK4E’s maximum latency it is clear to see how much better of a performer this SSD is over the HK4R. Even though the HK4R was very consistent in its performance, the HK4E’s maximum latency is significantly better during mixed and write only workloads. During 100% reads latency maximums ranged mid to high 2ms. During 65% reads the max latency jumps up to around 10ms, which is less than half of what the HK4R delivered and closer to the performance we have seen in Samsung’s offerings, though we see a bit more fluctuation here. From these results we can see that the HK4E is much better suited for write and mixed workloads than its lower endurance and performance rated counterpart.