I tested the DNS-325 with 1.01 firmware using our standard NAS test process with RAID 0 and 1 volumes.
The Benchmark summary below in Figure 11 shows Windows File copy write with a RAID 0 array measured 36 MB/s, dropping to 30 MB/s for RAID 1. File copy read for RAID 0 was much higher at 72 MB/s but not as high for RAID 1 at 45 MB/s.
Figure 11: DNS-325 Benchmark summary
The NASPT File Copy write benchmark for RAID 0 was not much different from Windows File copy at 34 MB/s while RAID 1 NASPT File Copy was a bit lower at 26 MB/s. NASPT File Copy reads for RAID 0 and 1 stayed in the 30 MB/s range at 37 MB/s and 34 MB/s, respectively.
The tougher NASPT Directory Copy tests yielded only 11 MB/s for write and 14 - 16 MB/s for read between both RAID modes.
There are no attached drive backup results, because the 325 doesn't support it. I was able to run an rsync backup using the Remote Backup standard Add On, which turned in a respectable 19 MB/s for the standard 4 GB ripped DVD folder. There are no iSCSI results because the 325 doesn't play that tune.
The RAID 1 File Copy Write and Read charts in Figures 12 and 13below are filtered to show only two-bay NASes. The DNS-325 is the only NAS in the chart to use the 1.2 GHz Kirkwood. (I have tested other 1.2 GHz Kirkwood NASes, but not two-bay.) So the closest comparisons will be 1 GHz Kirkwood NASes, which are the Iomega ix2-200, and NETGEAR Stora.
Most everything else you see in the chart are powered by Marvell Kirkwoods, except for the top three, which are Atom-based. The best of the Kirkwood NASes are the QNAP TS-219P+ and Synology DS211+, which come in behind the 325.
Figure 12: RAID 1 File Copy Write Comparison - two bay products
RAID 1 filecopy read is a similar story, with the 325 staying in the middle of the pack.
Figure 13: RAID 1 File Copy Write Comparison - two bay products
D-Link clearly hasn't swung for the performance fence with the DNS-325. They chose to save some manufacturing cost by using a older, slower Marvell SoC than used by the current top-performing Marvell-based NASes. But by throwing in a little more RAM, a little more flash and a bit faster CPU than the less-expensive DNS-320, they can support Add Ons. This will give the product a longer life via incremental feature additions, without the need for hacking it, which mainstream consumers are reluctant to do.
The additional features supported by the Add Ons allegedly justify the DNS-325's much higher (2X) price vs. the DNS-320. But to charge twice as much for a product that certainly doesn't cost twice as much to produce is really pushing the envelope. Given my experience with three of the six available Add Ons, I think that D-Link is going to take some flack when people start trying them out. It looks like someone has already discovered the effect of the old Squeezeserver version. (The downgrade issue that the Forum poster is describing isn't a biggie. That happens all the time when I occasionally switch from a local SqueezeCenter server to the web-based SqueezeNetwork and things work just fine.)
D-Link correctly pointed out that the more valid pricing comparison is vs. the DNS-323, which currently sells for around $200. Depending on where you buy, this is about the same (give or take $20 or so) pricing as the DNS-325. But the 2X comparison to the newer-generation DNS-320 is still valid.
I'll have to wait until D-Link sends a DNS-320 to see how it stacks up against the 325 for performance. But in the meantime, if you don't care about the Add Ons and want similar performance for similar money, consider Buffalo's LinkStation LS-WVL Pro Duo, which includes 2 TB of storage.