|QNAP TS-879U-RP 10GbE NAS Server|
|Reviews - Featured Reviews: Network|
|Written by Bruce Normann|
|Monday, 19 March 2012|
Page 7 of 10
ATTO Disk Benchmark Results
In addition to straight file transfer testing, I also ran the ATTO Disk Benchmark on the QNAP TS-879U-RP Turbo NAS Server, which is easy once a drive mapping is created on the host PC. 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. Our standard test settings for this benchmark use a queue depth of 4, and I also ran additional tests with the maximum queue depth available in this benchmark, which is 10. Heavy database usage can drive queue depth up to 32 or more, and this level is available on some other drive benchmarking suites. ATTO stops at 10, however, so we'll take a look at how much impact that has on the results.
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 performance pattern is seen. Neither the Read nor Write portions of the test can break past the 120 MB/s barrier put in place by the 1000BASE-T network connection. The good news is that the NAS reaches its peak performance with just 32kB data chunks.
As expected, the results with a 10GbE connection show huge gains. The Write speed reaches a peak of 457 MB/s and hits over 90% of that peak value at the 64kB step. It dips a little after the 1MB data size, but never drops below 92% of the peak. The Read speed hits an incredible peak of 679 MB/s at the two largest data sizes, and although it rises steadily during the test, it hits 95% of the peak value by the 512kB data chunk. This is an impressive performance improvement, and it pushes the TS-879U-RP NAS so far out in front of previously tested systems, that it almost creates a new category.
Adding in AES-256 bit volume encryption to the equation, the peak Write test results fall back to levels more like those we saw with the GbE network connection. The maximum write speed was 144 MB/s at the 128kB level. The write speed plateaued after the 16kB chunk size, where it first gets above 132MB/s. Using the Direct I/O setting, Read performance in this benchmark was not affected by the data encryption. Peak read speed came at the largest data level of 8192kB, and it actually surpassed the reading for the un-encrypted drives with a top tally of 698MB/s. Once again, top notch performance numbers that blow all previous units out of the water.
Increasing the Queue Depth from 4 to 10 didn't affect the peak performance numbers as much as it caused a bunch of variations at the different data chunk levels. The read speeds were particularly unstable, and you can see the green bars wandering all over the place in the chart below. They did hit a new high, though, with a top reading of 736 MB/s at the 256kB level. Write speeds were more uniform, with scores in the 430-456 MB/s range, starting at the rather low 32kB chunk size. I would call this good performance at the higher queue depth, and it's more than likely a testament to the 8 separate disks that make up the RAID 5 volume. It's no surprise that large disk arrays are the solution of choice for heavy database applications. The more drives you have in service, the more drive failures you're going to experience. Apparently, this is one case where the 24/7 performance advantage outweighs the occasional failure.
Before we leave the ATTO Disk Benchmark results, let's take a quick look at the QNAP Resource Monitor. During one of the benchmark runs with AES 256-bit encryption enabled, the read and write speeds are shown in stark contrast, laid on top of one another in real time. As the data chunk size increases, the read speed keeps going up, while the write speed is stuck in the 120-140 MB/s range. That's a result of the Direct I/O setting on the ATTO disk benchmark. A few minutes later you can see the traces for some timed 10GB file transfers, and the proof that without the Direct I/O path into the NAS, the read speeds fall back to normal levels.
ATTO has been used for a long time at Benchmark Reviews, since the early days of HDD testing, through the journey of trials and tribulations that accompanied the first several generations of SSDs, with all their benchmarking peculiarities. In the NAS arena, I appreciate the fact that it's one of the few drive testing programs that will work on a NAS that's been mapped to a drive letter by the host OS. It also has some nuances that need to be considered, but I believe there's strength in diversity. The more test applications I can use, the better understanding we can achieve about a product, IMHO.
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