The NSA325 v2 was tested with V4.70(AALS.0) firmware using our standard NAS test process. You can't do this automatically in the Charts, but I cut-and-pasted Benchmark Summaries for the original and v2 and put them side-by-side below. The highlighted benchmarks show large differences. Since the hardware is the same, the difference must be in the new firmware.
ZyXEL NSA325 Benchmark Summary
Taking a quick tour through the file copy benchmarks shows you won't take a performance hit if you opt to use RAID 1. The NASPT File Copy benchmarks show write throughput in the mid-to-high 60 MB/s range and read around 85 MB/s. Although this NAS can't fully use a Gigabit link's bandwidth, its performance is in line with what we've come to expect from Kirkwood based NASes.
It looks like the new firmware gooses USB 3.0 attached backup results a bit, with best throughput of 68 MB/s obtained with an NTFS formatted drive. I was pleased to find that ZyXEL now allows rsync backup to standard rsync servers, lifting the previous restriction of supporting backup only to other ZyXEL NASes. The 16 MB/s rsync throughput is again about par for the course for this class NAS.
The NSA325 v2 still doesn't support iSCSI, so there are no benchmarks shown for that test.
The NAS Ranker provides the best way to get a relative performance ranking based on all benchmarks measured. Filtering the ranker for single-core SoC processors and two drives reveals the original NSA325 v2 in third place behind Buffalo LinkStation 420 and ioSafe's N2, which is a Synology DS213 in a disaster-proofed enclosure. The original NSA325 has been archived, so no longer appears in the NAS Ranker. Like all archived products, however, you can still opt to see it in the charts using the Achived Products switch.
RAID 1 File Copy Write Performance - the ZyXEL NSA325 was 1.76 times faster than the D-Link DNS-325
Sorting the filtered view by ascending price is interesting. The v2's current $189 price actually makes it relatively expensive among dual-bay single-core processor SoC NASes. The Buffalo LinkStation 420 is both less expensive and slightly higher ranked for performance. But it has nowhere near the feature set of the ZyXEL.
In all, it still looks like ZyXEL's NSA325 in its new v2 form should be on your short list if you are looking for the most features you can get, as well as decent performance, in a dual-bay NAS that won't totally empty your wallet.