Performance
Updated 5/18/2009: Link to retest article.
Note: The TS-509 Pro has been retested on the new NAS testbed. See this article for a comparison to the TS-639 Pro and more information.
I put the 509 Pro through our iozone performance tests with all five drives configured in one Linear (JBOD) array and a RAID 5 array with 100 Mbps and 1000 Mbps LAN connections. No jumbo frame tests were done because jumbo frames are not supported. The system was loaded with five Hitachi Deskstar HDS721010KLA330 1 TB drives (7200RPM 3.0 Gb/s SATA 32 MB) that were provided by QNAP.
Figure 4 shows read and write benchmark results for filesizes from 32 MB to 1 GB with a 100 Mbps LAN connection. Except for some write caching effects at smaller filesizes, performance is right about at 100 Mbps wire-speed (12.5 MBytes/s).

Figure 4: 100 Mbps benchmark comparison
Figure 5 shows benchmark results for tests using a 1000 Mbps LAN connection. You can see that there is virtually no performance difference between JBOD (Linear mode) and RAID 5.

Figure 5: 1000 Mbps benchmark comparison
Figure 6 shows 1000 Mbps RAID 5 write competitive comparison for the 509 Pro and the three other products at the top of that NAS Performance chart: the Intel SS4200-E [reviewed], Thecus N5200 Pro [reviewed] and Synology DS508 [reviewed].

Figure 6: RAID 5 Write competitive performance - 1000 Mbps LAN
These current top four RAID 5 products are very similar in performance, but note that this is without jumbo frames. However, the Intel also does not support jumbo frames and the Thecus doesn't seem to gain much speed from them. And while the Synology's throughput does increase at some filesizes, the average large filesize performance is essentially the same.
At any rate, Figure 6 shows similar performance, but with the TS-509 Pro staying on top as file sizes increase, followed by the Intel SS4200-E.
Finally, Figure 7 shows 1000 Mbps RAID 5 read results for the same group of products. The 509 Pro has exceptionally flat performance out to 512 MB filesizes, with speeds exceeding 55 MB/s. The Thecus is clearly the (relative) laggard, while the Intel and Synology end up about even in average performance for the filesizes shown)

Figure 7: RAID 5 Read competitive performance - 1000 Mbps LAN
Closing Thoughts
Since they first entered the market, Thecus, Synology and QNAP have been battling it out for bragging rights to being the fastest RAID 5 NAS. It's a fun game to watch and the battle has been good in general for consumers, spurring better-known brands to raise their game and improve the peformance and feature sets of their products.
But high performance comes at a cost, as the 509 Pro once again shows. At around $850, it's significantly less than the $1000 Synology DS508, but still quite a chunk of change. And QNAP still has no U.S. office, online support only and limited distribution. So if you're uncomfortable dealing with smaller companies on big-ticket items, you should look elsewhere.
Updated 8/18/2008
QNAP said that they have a U.S. office under their parent company name IEI Technology USA Corp that handles sales, support and warehousing:
IEI Technology USA Corp.
168 UNIVERSITY PARKWAY
POMONA, CA 91768-4300
TEL: 909-595-2819
FAX: 909-595-2816
Email: This e-mail address is being protected from spambots. You need JavaScript enabled to view it
Still, if you have been eyeing Synology's DS508, but felt your wallet being stretched a bit too thin, you should take a look at the TS-509 Pro.
See the slideshow for more internal details






