Micron RealSSD P320h PCI Express SSD Review

As we've noted in our previous SSD coverage, though IOMeter is clearly a well-respected industry standard drive benchmark, we're not completely comfortable with it. The fact of the matter is, though our actual results with IOMeter appear to scale properly, it is debatable whether or not certain access patterns, as they are presented to and measured on an SSD, actually provide a valid example of real-world performance for the average end user or application workload. That said, we do think IOMeter is a gauge for relative available bandwidth with a given storage solution.  In addition there are certain higher-end workloads you can invoke on a drive with IOMeter, that you really can't with any other benchmark tool available currently.

IOMeter  I/O Subsystem Measurement Tool

In the following tables, we're showing two sets of access patterns; our Workstation pattern, with an 8K transfer size, 80% reads (20% writes) and 80% random (20% sequential) access and our Database access pattern of 4K transfers, 67% reads (34% writes) and 100% random access.

We decided we'd break out out IOMeter tests into a couple of groups, with IOs set to standard sector--aligned tests (default for the benchmark) and then 4K aligned IO requests for the same workloads and queue depths. 4K IO boundaries generally tend to align with NAND program page sizes, so, as you can see, performance scales dramatically.  Again, unfortunately we didn't have the Z-Drive R4 around for 4K aligned testing, in this scenario.  Regardless, in our 8K Workstation data transfer configuration, a mix of mostly read requests at 80%, the P320h shows killer performance almost doubling Intel's SSD 910 and coming within striking distance of the OCZ  Z-Drive R4. 

With our database access pattern, which is a larger mix of 4K write requests, along with 4K reads, the P320h showed a massive performance lead, with over three times the IO throughput of the SSD 910 in our 4K aligned tests.  Interestingly,  in our sector-aligned tests above this graph, the P320h was still getting its legs at higher queue depths and came close to matching the OCZ Z-Drive R4.

The workload you see represented in the IOMeter graph below has become an "industry standard"  configuration as of late, though we'd offer that it still should be taken with a grain of salt.  Again, what we're looking at here is a one set access pattern that is concurrently sprayed across the drive volume by IOMeter until the drive reaches its saturation point.  In this IOMeter run, we should note that drives were formatted. but left blank.  Specifically the P320h was secure erased and pre-conditioned, filling the drive with 128K writes in a raw state and the formatted before we ran the test.

Here, the Micron P320h falls just short of the Intel SSD 910 in 4K random writes.  We will note, however, that the P320h offered in excess of 515K IOPs in 4K random reads under this exact test condition, which is similar to what we saw in our database test workload.  Micron's P320h SSD offers significant, industry-leading strength in high queue depth random read performance.