iSCSI Performance Testing
Four of the systems support iSCSI. The Thecus N2810, another Intel-based system, joins the group for this round. The three systems that support encrypted folders carry over, as well.
Many casual computer users have never heard of the iSCSI interface, or are even aware of what it does. The technology allows users to share a block of the storage space on the NAS with PCs as a local storage volume. Your desktop computer sees the space and manages it exactly as a hard drive mounted inside the chassis. The storage volume then presents itself to the user as a drive letter, similar to a secondary hard drive.
Unfortunately, some software will not install to mapped storage. iSCSI reports as a physical drive in Windows, which is an important technical distinction with a deeper underlying impact that affects how the operating system manages the drive. iSCSI also supports native command queuing (NCQ), which is a performance-enhancing feature that is not available for traditional mapped storage volumes. NCQ allows the system to reorder the incoming data requests to optimize, and reduce, head travel when the HDD retrieves the data. This increases performance when the drive returns the data to the host system.
Sequential Read Performance
iSCSI performance is often better than mapped storage, and all of the systems provide similar performance while connected via iSCSI, too. The Thecus delivers a solid opening round with iSCSI by delivering slightly better performance than the other systems in two of the three tests.
Sequential Write Performance
The sequential write test highlights the separation between the Intel and Marvell processor systems when writing data. The Synology DS216j offers amazing value, but you shouldn't expect it to provide the same performance as the Intel-based systems.
Sequential Mixed Workload Performance
In general, iSCSI allows systems to provide higher performance than SMB does. The native command queuing (NCQ) support provides smoother performance for a more consistent experience with application workloads.
Random Read Performance
Windows applications rely heavily on 4KB updates, so any Windows application running on a NAS will be 4KB heavy. It's also possible to use these systems for VMware, but it optimizes the data traffic for 8KB random data. The two Synology systems scale the best during random read workloads.
Random Write Performance
The Asustor and Thecus systems perform better with random data writes. If anything, the tests today show that no system outperforms another in all workloads or formats. Each system has a strength somewhere, even if it is just its pricing or its performance during basic usage patterns.
Random Mixed Workload Performance
Most of the systems group together during the mixed random workload test. The Thecus N2810 trails with lower IOPS performance, but it still delivers a strong showing.
iSCSI Desktop Workloads
In these tests, we measure the amount of time it takes to complete each task. The results are very close to, if not a little faster, than a local 7,200 RPM hard drive installed in the host system. The difference is that the NAS provides a resilient and redundant storage pool with less of a chance of data loss.
