|QNAP TS-879U-RP 10GbE NAS Server|
|Reviews - Featured Reviews: Network|
|Written by Bruce Normann|
|Monday, 19 March 2012|
Page 6 of 10
Intel NASPT Test Results
NASPT brings an important perspective to our test protocol, as it is designed to measure the performance of a NAS system, as viewed from the end user's perspective. Benchmarks like ATTO use Direct I/O Access to accurately measure disk performance with minimal influence from the OS and the host platform. This provides important, objective data that can be used to measure raw, physical performance. While it's critical to measure the base performance, it's also important to quantify what you can expect using real-world applications, and that's exactly what NASPT does. One of the disadvantages of NASPT is that it is influenced by the amount of memory installed on the client, and it was designed for systems that had 2-4 GB of RAM. Consequently, two of the tests give unrealistic results, because they are measuring the speed of the buffer on the client, instead of the actual NAS performance. For that reason, we will ignore the results for "HD Video Record" and "File Copy to NAS".
First, let's look at the results with the standard GbE interface, and un-encrypted drives. This is sort of the baseline, as we want to see how much AES-256 encryption reduces the performance, and we want to see how much the enhanced Ethernet connection improves the performance. With the basic GbE interface in place, a familiar pattern is seen. No individual test pushes past the ~120 MB/s barrier, but several hover just below it. Several of the tests have very low transfer rates, and that's due to the nature of the test. The Content Creation test for example, simulates a user creating a web page, accessing multiple sources for the content. This kind of NAS device is built for handling in the neighborhood of 30 users doing content creation, so I'm a little suspicious about this test, but we'll see how it works with multiple scenarios before we rule it out. The Directory Copy tests use several hundred directories and several thousand files to test a typical backup and restore scenario.
Moving up the performance ladder, with the 10GbE connection in place, the results show significant gains across the board. The HD Video Playback tests all take full advantage of the larger Ethernet pipeline and posted improvements on the order of 4x, which is the same effect we saw in the earlier file transfer tests. Content Creation got a 2.5x boost, while the Directory Copy tests got a 2x improvement on copies from the NAS and performed 3.5x better on copies to the NAS. Clearly there are some significant factors in the test protocols that are emphasizing different aspects of NAS performance, otherwise all the results would be in the 400-500 MB/s range. As we generate more data with this benchmarking tool, we should start to see some performance patterns emerging.
Adding in AES-256 bit volume encryption to the equation, the peak test results fall back to levels more like those we saw with the GbE network connection. The more context-sensitive tests, like Content Creation and Directory Copy to the NAS all posted decent gains, though. On average, the numbers are about 50% better than the baseline performance with the GbE connection. Unfortunately, the average with encrypted drives is also only about half of what is possible without it. That's quite a performance hit, so be very sure to make an informed and rational decision before deciding to encrypt all your data. Most applications for this kind of NAS system are going to have a number of physical security safeguards in place that would negate the need for encryption. Most data centers are card-key access only, and have cameras pointed down every aisle, but all it takes is one very smart, rogue employee to make everyone wish that someone had taken the extra step to secure their data.
To wrap things up, here's a consolidated chart of the "Fast" NASPT tests, and another for the "Slow" ones. First, the tests with relatively fast transfer rates. Once again, the performance of eight un-encrypted disks pumping data through a 10 Gigabit pipe is miles ahead of the alternatives. The larger bandwidth of 10GbE also gives the AES-256 encryption tests a small advantage over the baseline performance of the TS-879U-RP with its integral GbE connections. It's also interesting to see how the AES-256 performance goes up slightly as the video playback speed increases from 1x to 4x.
The "Slow" tests show a much narrower range of performance variation between the three different configurations. It also shows that most of these benchmarks got a more significant boost on the AES-256 scores than we saw in the "Fast" test results. The Directory Copy In results are a bit of an anomaly, but aren't completely out of the realm of possibilities. It does make me wonder if the metadata for the directories is encrypted. That might be a problem.....
Before we leave this benchmark, take a look at the network bandwidth chart from the QNAP Resource Monitor, as it records the data flows in and out of the NAS during the NASPT benchmark. The green trace is for data coming into the NAS, and the pink trace is for data leaving the NAS. Note the fifth peak, which represents the data for "HD Playback & Record" and you can see data simultaneously going into and out of the NAS. The big gap before any more data transfer is all the machinations going on in the Content Creation test - all that human simulation stuff that keeps the overall transfer rate low for this benchmark.
This was my first real set of official tests with the Intel NASPT benchmarking tool, and I'm reasonably happy with the results. I'm not too pleased that two of the tests are so dependent on the amount of memory in the host PC, to the point of making their test results completely unusable. I'm also not willing to hobble the Windows 7 test bench to 2GB of RAM just to run this test suite. The fact that 10 of the 12 tests are not affected by this issue means I will choose to ignore the HD Video Record and File Copy to NAS results unless a patch is issued to fix this problem. All of the other tests give predictable and meaningful results that represent real-world scenarios, so I think I'll continue to use this benchmark in the future.
NAS Comparison Products