|QNAP TS-219P+ NAS Network Server|
|Reviews - Featured Reviews: Network|
|Written by Bruce Normann|
|Thursday, 30 June 2011|
Page 9 of 13
Benchmark Reviews primarily uses metric data measurement for testing storage products, for anyone who is interested in learning the relevant history of this sore spot in the industry, I've added a small explanation below:
The basic unit data measurement is called a bit (one single binary digit). Computers use these bits, which are composed of ones and zeros, to communicate their contents. All files are stored as binary files, and translated into working files by the Operating System. This two number system is called a "binary number system". In comparison, the decimal number system has ten unique digits consisting of zero through nine. Essentially it boils down to differences between binary and metric measurements, because testing is deeply impacted without carefully separating the two. For example, the difference between the transfer time of a one-Gigabyte (1000 Megabytes) file is going to be significantly better than a true binary Gigabyte (referred to as a Gibibyte) that contains 1024 Megabytes. The larger the file used for data transfer, the bigger the difference will be.
Have you ever wondered why your 500 GB hard drive only has about 488 GB once it has been formatted? Most Operating Systems utilize the binary number system to express file data size, however the prefixes for the multiples are based on the metric system. So even though a metric "Kilo" equals 1,000, a binary "Kilo" equals 1,024. Are you confused yet? Don't be surprised, because even the most tech savvy people often mistake the two. Plainly put, the Kilobyte is expressed as 1000 bytes, but it is really comprised of 1,024 bytes.
Most network engineers are not fully aware that the IEC changed the way we calculate and name data chunks when they published the new International Standards back in December 1998. The International Electrotechnical Commission (IEC) removed the old metric prefixes for multiples in binary code with new prefixes for binary multiples made up of only the first two letters of the metric prefixes and adding the first two letters of the word "binary". For example, instead of Megabyte (MB) or Gigabyte (GB), the new terms would be Mebibyte (MiB) or Gibibyte (GiB). While this is the new official IEC International Standard, it has not been widely adopted yet because it is either still unknown by institutions or not commonly used.
NAS Testing Methodology
All the NAS devices we test cannot accommodate all the different disk configurations, so our current test protocol has been based on two of the most popular setups: a basic (single) disk and RAID-5 configurations. Since this two-bay device doesn't support RAID 5, I only tested the single-disk mode this time. Each NAS device was upgraded to the very latest firmware by flashing the DOM with binary files downloaded from the QNAP website. The recommended firmware was the same for all the devices under test: v3.4.3-0520T
Connected directly to the Realtek 8112L Gigabit LAN controller in the test-bench system by a ten-foot CAT6 patch cable, the NAS product receives one test transfer followed by at least three timed transfers. Each test file was sent to the Western Digital Caviar Black 750GB (WD7501AALS) hard drives installed in the NAS for a timed write test, and that same file was sent back to a Western Digital VelociRaptor 150GB 10,000 RPM (WD1500HLFS) hard drive in the test system to perform a read test. Each test was repeated several times, the high and low values were discarded and the remaining results were recorded and charted.
This is the start of NAS testing where we are going to exclusively use Windows 7 as the testing platform for the host system. The performance differences between Win7 and XP are huge, as we documented in our QNAP TS-259 Pro review. The adoption rate for Win 7 has been very high, and Benchmark Reviews has been using Win 7 in all of our other testing for some time now. It's definitely time to make the jump for NAS products.
The two transfer tests: read and write, were conducted on each NAS appliance using the 1 GB file and then a 10 GB file. Additionally, a second set of tests were conducted with Jumbo Frame enabled, i.e. the MTU value for the Ethernet controllers was increased from 1500 to 9000. All the NAS products tested to date in the Windows 7 environment have supported the Jumbo Frame configuration. I also include a baseline of sorts, which is the internal file transfer from the Corsair P64 SSD to the Western Digital 150GB VelociRaptor installed on the Intel P55 motherboard SATA connections, where the Intel P55 chipset provides the SATA 3Gb/s interface, and a Marvell 88SE9123 controller provides two ports of SATA 6Gb/s connections.
NAS Comparison Products