SNIA IOPS TESTING
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 4KiB 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.
- Preconditioning: 3x 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)
This test is normally used for single SSD testing, but it does a good job of showing numerous transfer sizes, mixed operations and quick workload transitions in a single graph. The results for the Adaptec/SMART solution are so outstanding it’s hard to know where to begin. The first thing that stands out is that the 100% read operations stayed right around 360,000 IOPS from 0.5 to 16KiB. The 100% write operations didn’t do quite as well, but the 4 and 8 KiB results were nearly identical.
The 4KiB performance was another result that stood out. Even with a 50/50 mix, the Adaptec/SMART solution still recorded almost 350,000 IOPS, down only slightly from its 368,000 IOPS max.