Synology does offer four-bay devices such as the DS414 and DS415+, but unusually also has five-bay NAS drives in its extensive range – usually aimed at more data-hungry applications demanded by businesses and home power users. The DS1515+ is the latest such five-bay NAS from Synology, derived from the original DS1010+ launched in 2010, and now sporting a quad-core Intel Atom processor running at 2.4 GHz.
Synology DS1515 review: Features and specs
What we have here though is the DS1515+ ‘lite’, based on the same chassis but with a lower-spec ARM processor and a little trimming to the ports arrangement. Instead of the usual low-powered Intel x86 processor, noted for quite usable file-serving speed in pre-built NAS devices, the ARM processor is an even cheaper option for the manufacturer to install, helping to cut the final retail price; and there’s also the potential for savings in your pocket, with reduced electricity costs from the more frugal processor architecture. The Annapurna Labs Alpine AL-314 processor is something of a mystery although it reveals itself internally as based on the 32-bit ARMv7 rev 4, as commonly found in mobile devices like Google Android smartphones. The Annapurna Labs system-on-a-chip also includes a hardware encryption engine, which means you could select the encrypted-volume option in the DSM software without incurring the massive slowdown that software crypto otherwise creates when activated. A floating-point unit (FPU) is also available to keep up overall speed. For system memory, the DS1515 has 2GB DDR3 RAM fixed, where the DS1515+ can be upgraded to a total of 6GB. The DS1515 has four gigabit ethernet ports and two eSATA ports, in common with plus version, but only two rather than four USB 3.0 ports. Both machines have the capability to be docked with up to two additional bare five-bay chassis – the first 15 in the product name indicates a total of 15 disks can be run from the core NAS system; the second 15 shows the year of release: 2015. The second key component of the NAS drive is its software, and here we find the usual DSM operating system, now in its version 5.2. We have explored its manifold features and ease-of-use before in preceding Synology NAS reviews – suffice to say this remains a strong reason to consider a Synology network drive.
Synology DS1515 review: Performance
The Alpine processor showed it had plenty of real-world power in a straightforward sequential speed test, up to the gigabit-LAN limit for both reads and writes. We set up the Synology DS1515 with four 2TB WD Red hard disks, configured in the default SHR array – Synology Hybrid RAID, which here behaves like a traditional RAID 5 array. In Windows and connected via SMB, the ATTO Disk Benchmark test showed sequential transfers up to 119MB/s, for all data from around 32kB to 8MB. With four threads available its 4kB read/write results were an impressive 18.6- and 25.6MB/s respectively. CrystalDiskMark 3.0 rated sequential reads and writes at 110MB/s, while 4kB random reads and writes reached 10MB/s; not a bad result for a single thread. Expanding to a queue depth of 32 threads, transfers now reached an even healthier 55MB/s reads and 44MB/s writes. For Mac users, we tried both AFP and SMB connections. By default, most Mac users will find themselves using the Apple Filing Protocol, although our experience has shown that with network drives it can be beneficial to force a connection over Microsoft’s Server Message Block, especially when many small-file transfers will be in play. In the case of Synology’s DiskStation Manager operating system, this is not really an issue though – both protocols scored well here, with AFP sequential transfers up to 110MB/s (106MB/s SMB) while 4 kB random read/write results were essentially the same at around 12MB/s (random 4kB read) and 6.5MB/s (random 4kB write). Power consumption was relatively low, reaching 30W with the system in use with its four WD disks, and falling to 18W when the NAS was idle and the disks had spun down.
