We've retested the QNAP TS-559 Pro with new firmware and updated the NAS Charts.
QNAP found that our previous test results we much lower than their internal tests using similar test methods. After investigation, they found that write cache was not enabled on our review sample.
QNAP has enabled write caching for EXT4 volumes since they made EXT4 the default for RAID volumes. But a bug in the 3.2.6 Build 0423T firmware we used for testing did not properly enable it by default. So QNAP released 3.2.7 Build 0525T firmware and requested a retest, which we performed.
The iozone benchmark plots for the retest are shown below, along with the original results in the graphic below it.
TS-559 Pro Throughput vs. file size - retest
The main difference in results is a boost in throughput at 512 MB and larger file sizes. But since we don't include anything over 125 MB/s in our calculation, the new charted average write performances include only two data points (2 GB and 4 GB).
TS-559 Pro Throughput vs. file size - original test
Average RAID 5 write performance using a Gigabit Ethernet connection now averages 105.5 MB/s (vs. 85.2 MB/s before) for file sizes between 32 MB and 4 GB, with cached behavior not included in the average calculation. Average RAID 5 read performance is still significantly lower, but improved, measuring 74.1 MB/s (vs. 65.4 MB/s). So the TS-559 Pro now ranks above the TS-459 Pro in the RAID 5 charts.
RAID 5 File copy performance using our Vista SP1-based test now show the TS-559 Pro faster than the TS-459 Pro, with 92.1 MB/s (vs. 66.3 MB/s before) write speed and 95.3 MB/s (vs. 71.9 MB/s before) read.Use the NAS Charts to further explore the TS-559 Pro's performance and compare it to other products.