QNAP TS-451 Turbo NAS Server Review


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1GB RAID 5 Test Results

If you’ve got more than three HDD spindle to put in play, it makes sense to use one of the more advanced RAID configurations. RAID 5 is one of the most popular setups, primarily due to the balance it exhibits between capacity and redundancy. Not surprisingly, most NAS units that can support more than three HDDs also support RAID 5, so it makes sense to use it for test purposes. Most NAS products that can support RAID 5 go beyond the minimum number of drive bays, to a total of four, so that is the number of drives that I typically use to test with, even though I could get by with only three.

The unit that’s the subject of this review is the first set of results, right on top where they’re easier to find. All these results are based on a single workstation interfacing with the NAS, and the larger models in this group are designed to handle data requests from multiple servers at one time. That doesn’t invalidate these results, because it’s still important to know what level of performance is available for a single user, as well as the overall aggregate. Before we look at the benchmark results, I want to show you the typical NAS CPU and Memory loading that occurred during these timed file transfer tests.  As you can see, they are both quite low, and they stayed that way throughout the whole test. This chart is from a new widget that’s been included since the QTS 4.0 application, which you can put on your desktop to monitor system resources, network activity, etc.  The old resource monitor screens are still available in the main software, and offer run charts instead of real-time “meters”.


Given all the behind-the-scenes processing that goes on to calculate parity bits for RAID 5, these results show that the QNAP TS-451 Turbo NAS has more than enough power under the hood to keep the drives performing at their potential during read and write operations. With all the NAS devices in this comparison, the real trick is trying to get as much throughput past the 1 GbE network interface. Any of the NAS models I’ve tested with a 10GbE interface had results that easily tripled the performance available with the GbE interface.  CPU and memory utilization on the TS-451 were always quite low during READ tests.  Read performance is strong with this system, which is a real bonus if you plan to use it as frontline storage. You won’t have network storage performance that’s on par with the local SSD in a high-end PC, but 117.6 MB/s is still very fast.  If you’re going to use it primarily as a backup system, you also want top-notch write performance, which we’ll test next.


The 1 GB RAID 5 disk write test shows very strong results, as well. The TS-451 puts in a chart-topping result at 116.3 MB/s. It’s well known that RAID 5 write performance can be a weak point, with all the computation overhead involved and the extra parity bits that need to be calculated and written to each of the drives. The only way to overcome that is with raw computational horsepower, and there may have been concerns that the low-power Bay Trail-D CPU in the TS-451 wouldn’t be up to the task.  These results clearly show that Intel has finally designed a powerful replacement for the Atom in its low-power lineup. You only have to look at the old TS-419P II model to see how the stronger CPU in the TS-451 provides twice the performance at the system level.


Next up is 10 GB (1000 metric megabytes / 10,000,000,000 bytes) file transfer testing. Using the 4-disk RAID 5 configuration in each NAS, and a single Gigabit connection, network throughput will be put to the test, and the effect of any system or hardware caches will be minimized. This is almost pure sequential disk access testing, combined with a real-world application that gets repeated millions of times a day – file transfer.

10GB RAID 5 Test Results

Looking at Read tests with a single 10GB file, the TS-451 nudges ahead of the ASUSTOR AS-604T and wins top place in Read performance with an average Read speed of 121.7 MB/s. No worries about the new low-power CPU in the TS-x51 series not having enough performance, that’s for sure.  The performance of all these NAS products is still constrained by their GbE connections. This chart looks a whole lot different when some of the devices are equipped with better network interfaces. For 99% of home scenarios though, Gigabit Ethernet is the top transfer speed that will be supported by the rest of the networking equipment.


Looking at write tests with a single 10GB file, the TS-451 comes out on top again by a small margin, with an average Write speed of 119.0 MB/s. I used to say that if you’re writing large files to a NAS running RAID 5, you can’t afford to scrimp on system hardware; you need the biggest, baddest CPU you can afford.  This Celeron-based NAS has made me re-think that a bit, in favor of a more optimized systems approach. In this case, the SOC approach eliminates the Platform Controller Hub from the mix, and the direct connection of the CPU/SOC to the Asmedia SATA 6Gb/s controllers works very well. The TS-451 has just the right blend of internal components to maximize the performance v. cost equation.  The lower cost of the tower configuration hardware, compared to a rack mount form factor, helps improve the cost-benefit ration even further. This definitely helps if you need the additional capacity of one of the larger models in the TS-x51 lineup, with six or even eight bays.


All in all, after these series of file transfer benchmarks, I have to give a lot of credit to QNAP for delivering almost all of the performance of their high-end business class tower models, in a lower cost format. Yes, the chassis is cheaper, and the CPU is less powerful, and you’re only ever going to get GbE transfer speeds to it or from it, but that’s still a decent recipe for NAS success. If you’re going to remain in a GbE network environment for the next five years, and most homes are, it’s OK not to over-engineer your storage servers to provide more throughput than they can effectively deliver to the rest of the network.

Next, let’s take a look at test results from a benchmark suite that’s specifically designed to measure NAS performance, using test scenarios that cover a wide range of use cases. I’m talking about the NASPT tool from Intel.

NAS Comparison Products


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  1. Piotr Z.

    If I’ve read the screenshot of ATTO correcty, you’ve just measured your C drive on SSD 🙂 1Gbit interface is exactly that – 1Gbit = theoretical 125MB/s. With the overhead it will max out on 110-180MB/s which you got in other softwares. I would suggest fixing that part of otherwise great review 😀

  2. Bruce

    Well, that might explain the very strange results I got….. Thank you so much for pointing that out. I will redo that test and post the true results.

  3. jamief

    QNAP suggest 3 possible usb tv tuners for use with this model….namely UPMOST DVB192A HD; Hauppauge Win TV Nova_T Stick (Device: 70019;HW rev DiF4) or Asus My Cinema U3100 Mini. I mistakenly bought a QNAP USB tv Stick when I originally acquired the above unit, thinking that it would naturally be compatible. Some of the above sticks are difficult to either isolate or acquire in UK and I was wondering if anyone else with similar NAS has had any luck with any other usb stick.

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