Akasa M.2 SSD Enclosures Reviewed: Giving Spare Drives a New Lease of Lifeby Ganesh T S on September 22, 2021 8:00 AM EST
Synthetic Benchmarks - ATTO and CrystalDiskMark
Benchmarks such as ATTO and CrystalDiskMark help provide a quick look at the performance of the direct-attached storage device. The results translate to the instantaneous performance numbers that consumers can expect for specific workloads, but do not account for changes in behavior when the unit is subject to long-term conditioning and/or thermal throttling. Yet another use of these synthetic benchmarks is the ability to gather information regarding support for specific storage device features that affect performance.
Both SATA storage bridges are able to sustain the maximum possible transfer rates from SATA SSDs - in this case, the WD Red SA500 is able to provide around 510 MBps writes and 535 MBps reads for the ATTO workloads. The VL716-enabled AK-ENU3M2-02 is able to provide more consistent write performance compared to the AK-ENU3M2-04 using the Realtek RTL9210B-CG.
|ATTO Benchmarks - SATA|
The NVMe bridges are both able to sustain around 1 GBps reads and writes. The ASMedia ASM2362-enabled AK-ENU3M2-03 provides slightly higher peak performance compared to the AK-ENU3M2-04 for the ATTO workloads. ATTO benchmarking is restricted to a single configuration in terms of queue depth, and is only representative of a small sub-set of real-world workloads. It does allow the visualization of change in transfer rates as the I/O size changes.
|ATTO Benchmarks - NVMe|
CrystalDiskMark. for example, uses four different access traces for reads and writes over a configurable region size. Two of the traces are sequential accesses, while two are 4K random accesses. Internally, CrystalDiskMark uses the Microsoft DiskSpd storage testing tool. The 'Seq128K Q32T1' sequential traces use 128K block size with a queue depth of 32 from a single thread, while the '4K Q32T16' one does random 4K accesses with the same queue configuration, but from multiple threads. The 'Seq1M' traces use a 1MiB block size. The plain 'Rnd4K' one uses only a single queue and single thread . Comparing the '4K Q32T16' and '4K Q1T1' numbers can quickly tell us whether the storage device supports NCQ (native command queuing) / UASP (USB-attached SCSI protocol). If the numbers for the two access traces are in the same ballpark, NCQ / UASP is not supported. This assumes that the host port / drivers on the PC support UASP.
|CrystalDiskMark Benchmarks - SATA|
The pure-SATA storage bridge shows better write performance, while the Realtek solution shows better reads - both sequential and random. Both bridges support UASP, as we can see the significant gulf in the 4K random accesses for Q1T1 and Q32T16.
|CrystalDiskMark Benchmarks - NVMe|
Both NVMe bridges behave similarly for sequential accesses. However, the ASMedia solution exhibits much better performance for high queue-depth 4K random accesses compared to the Realtek solution.