How I tested
My test lab consisted of a mix of servers including two HP ProLiant MicroServers running Windows Server 2012 and a Dell PowerEdge R715 running Windows Server 2012 R2, an HP 2920-24G switch, and a CyberPower UPS for testing orderly shutdown. I used multiple Hyper-V instances on the servers to generate network traffic for load testing. Before testing I updated the NAS units to the latest firmware release. In the case of the QNAP unit, I also tested a beta release of QTS 4.1.
For performance testing I used Iometer. While some might say Iometer is getting long in the tooth, it is still one of the few open source tools commonly used to compare the performance of different storage systems. To create the tests, I used the OpenPerformanceTest32.icf Iometer configuration file available on the vmktree.org website. A handy Web-based results interpreter on the same site lets you paste the contents of the Iometer output file and see the results in a nice summary table.
Iometer uses either an unpartitioned disk, or a single data file named iobw.tst by default, for all operations. If the file does not exist on the target drive, Iometer will proceed to create one for you. In an attempt to produce consistent results with the same base file I used a program called TestFileCreator.exe (available here) that will quickly allocate a file of a specified size.
The OpenPerformanceTest32.icf configuration file uses four different scenarios to test maximum throughput and random read/write traffic. The main objective of my performance testing was to subject each NAS system to the same mixed workload for comparison purposes, not to drive the storage systems beyond their network or storage bandwidth capacity. As you can see from the charts below, the LenovoEMC and Netgear systems were the strongest performers, though the Netgear also turned in the highest latency in two of the tests.
Each of the units we tested had a set of common features you might expect to find on any business-grade storage box. All four units support SATA drives only and provide removable disk trays to install any typical 3.5-inch drive. The drive trays in the LenovoEMC, Netgear, and QNAP units have screw holes for 2.5-inch drives on the bottom and 3.5-inch drives on the top. This makes it really easy to install drives of either size — including SSDs, which generally come only in the 2.5-inch form factor. Infortrend provides a 2.5-inch adapter, which costs extra.
The systems run either a quad-core Intel Xeon or a dual-core Intel Core processor and between 4GB and 8GB of memory. (All but the QNAP sported 8GB of RAM.) All contain a minimum of two 1GB Ethernet ports with 10GbE ports as an option. The LenovoEMC and Netgear units have four 1GB Ethernet ports as standard equipment. Dual redundant power supplies come standard on all units, along with USB and serial ports to connect to a UPS. For connecting external drives, the LenovoEMC and Netgear units include USB ports on the front for easy access. The QNAP includes eSATA and USB 3.0 ports on the rear.
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