I tested the DS1512+ with DSM 4.0-2228 firmware, using our NAS test process with RAID 0, 5 and 10 volumes. As is our standard practice, I used only four drives configured into each volume type.
Windows File Copy tests were pretty consistent for RAID 0, 5 and 10, with the lowest result of 94 MB/s for RAID 0 write. Highest filecopy throughput was 106 MB/s from RAID 5 read.
Synology DS1512+ DiskStation benchmark summary
Intel NASPT File Copy results were about 20 MB/s higher for writes across the RAID modes, but about 15 MB/s lower for reads. Highest NASPT write throughput was 127 MB/s for RAID 5 write and lowest read was 91 MB/s. Note that the highest possible throughput from a Gigabit connection is 125 MB/s, so there is probably some write cache effect baked into the results.
iSCSI performance of 98MB/s for write and 74 MB/s for read places the 1512+ among the top five of all RAID 5 capable NASes tested.
Since Synology NASes have built-in FAT, EXT3 and EXT4 formatting for external drives, I was able to run a full set of backup tests. USB 2.0 tests to our standard Iomega UltraMax Pro drive in RAID 0 produced mid-20 MB/s speeds that are about the limit of that connection's capacity. Fastest eSATA backup of 84 MB/s was obtained with the Iomega drive FAT-formatted. But USB 3.0 was close behind with a best case of 80 MB/s with a WD MyBook 3.0 drive formatted in NTFS. By comparison, Network backup to a DeltaCopy target on our NAS Testbed system was downright poky at only 37 MB/s.
To see how the DS1512+ fared against other RAID 5 capable NASes, I ran Windows RAID 5 Write and Read File Copy charts shown below, filtered to show only five-bay products. Since the only other Intel D2700-powered NAS, Thecus' N4800 is only a four-bay NAS, it doesn't show in these charts.
Synology DS1512+ DiskStation RAID 5 File Copy Write comparison
Running unfiltered versions of the same benchmarks ranked the DS1512+ and N4800 at number 2 and 7, respectively, for write and number 2 and 11 for read.
Synology DS1512+ DiskStation RAID 5 File Copy Read comparison
Clicking through the various benchmarks looking at all RAID 5 capable products consistently showed the 1512+ ranking in the top 5 of each benchmark.
Use the NAS Charts to further explore and compare the DS1512+'s performance
Five-bay NASes aren't that common and are designed primarily for folks who like a hot-swap spare for four-drive RAID 5 volumes. Among the five products we've tested, the DS1512+ is priced right up with similar QNAP products like the TS-559 Pro II at around $800, but which aren't expandable.