Test Setup

Our test system (client PC) consists of the following components:


As you can see, we use a pretty strong test system with an ultra-fast OCZ Vertex 4 SSD from which all tests are executed to eliminate all bottlenecks on our side, since this specific SSD can achieve up to 560 MB/s read and 510 MB/s write (sequential).

Methodology

We use three different programs to evaluate the performance of the NAS. The first is Intel's NAS Performance Toolkit. Intel was kind enough to build a NAS performance toolkit and not only release it for free to the public, but also provide its source code. The only problem of this toolkit is that using a client PC with more than 2GB of memory will heavily affect two test results ("HD Video Record" and "File Copy to NAS") since both actually measure the client's RAM buffer speed and not the network speed, so we set the maximum memory of our test PC to 2GB via msconfig's advanced options. We also exploit its batch run function, which repeats each selected test for five turns and uses the average reading as the final result.


The second program is custom-made. It performs ten basic file-transfer tests and measures the average MB/s speed for each. To extract results that are as accurate as possible, we run all selected tests ten times and use the average as the final result.

We also use the same program to run our multiple client tests (up to ten clients are supported by one server instance of the program). The server program runs on the main workstation/server and all clients run the client version of the program. All are synchronized and operate in parallel, and all clients report their results to the server after the tests are finished. The server then sums them up, transferring all results to an excel sheet for the generation of the corresponding graph(s).


The third program we use in our test sessions is ATTO, a well-known program for storage benchmarks. Since ATTO cannot directly access network devices, we are forced to map a shared folder of the NAS to a local device.