Review: Qnap TS-251B

Test Methodology

Notes

All comparison servers are tested using a single Gigabit Ethernet link with jumbo frames disabled and are connected to our test client and network via a TP-Link TL-SG1024 switch.

Server and storage benchmarks are fraught with numerous variables, ranging from disks used, file system, network equipment and of course the number of connected clients. All NAS units tested prior to August 2018 were done so using 4TB WD Red hard disks, or in the case of fully-populated units, any drives supplied by the manufacturer. As of September 2018, we have migrated our test methodology to include newer 8TB Seagate IronWolf disks; the Synology DS918+ is the first NAS to be tested with the higher-capacity drives.

To provide a look at potential performance, our first benchmark is the freely available and widely used CrystalDiskMark. Our second benchmark - NAS Performance Toolkit, developed by Intel - is a file-system exerciser designed to provide performance comparisons between network storage devices. Intel's utility focuses on user-level performance using real-world workload traces gathered from common applications. NASPT reproduces the file-system traffic observed in various traces onto a chosen storage device and records performance in MB/s.

Last but not least, we measure NAS power draw during three states; under load, idle and standby mode if applicable, while a noise reading is taken using a PCE-318 meter.