We would like to thank Synology for supplying the review sample.
Synology's Plus series currently lists eight products tailored around the needs of small and medium business environments. The recently released DS916+ can hold up to nine HDDs with an expansion unit (the DX513), and its quad-core CPU is pretty strong as far as NAS servers are concerned. It can be had with either 2 GB or 8 GB of RAM and is clearly a pro-level NAS. However, if you are an enthusiast and need something powerful for your home, the DS916+ will easily fit the bill. Two Gigabit Ethernet controllers and the CPU's AES-NI hardware encryption engine supposedly allow for transfer speeds in excess of 200 MB/s with even encrypted files, and the CPU's hardware-accelerated transcoding engine allows you to transcode and stream H.264 4K / 1080p content to all your multimedia devices. Please note that Plex currently doesn't support this CPU's hardware transcoding engine, though, so make sure to use Synology's application to stream high resolution and bit rate content since it does exploit the CPU's encoding capabilities.
This NAS only seems to lack an HDMI port. Synology doesn't want to offer this very useful port with its products since it claims that streaming is the only way for a NAS to handle multimedia content. However, an HDMI port isn't only useful in multimedia-specific usage scenarios since it can also be used for local administration. As such, we strongly advice Synology to take another look at this matter to hopefully follow in the footsteps of other NAS vendors who do offer HDMI ports with most of their products.
One of the strongest assets of a Synology NAS is without a doubt the amazing DiskStation Manager, or DSM OS for short. After many years of development, DSM is very mature and stable, offering a plethora of options. You don't need to be an expert to take advantage of its functions and it's very light on resources. Another strong point is its Btrfs and standard ext4 file system support. The ext4 journaling file system is currently the most popular for Linux distributions, but within the last few years, some other file systems with more capabilities have emerged to address some of ext4's shortcomings. One of these fresh filesystems is Btrfs, a copy-on-write filesystem, or "COW", with support for a maximum file size of 16 EiB instead of the 1 EiB in ext4. Btrfs includes other very interesting features like snapshots, pooling, and checksums. One of the most interesting features of Btrfs is snapshot, a special type of subvolume that doesn't make copies of files but shares the data and metadata of the subvolume, which makes it very fast and takes very little space. A Btrfs subvolume's size isn't static since its space is dynamically allocated from the storage pool according to the data that is added or removed. Subvolume creation is also pretty easy, and a subvolume can even have nested subvolumes of its own. By default, there is always a top-level subvolume, which is mounted with all of its own subvolumes, but you can change the default subvolume to allow for a specific subvolume to be mounted without having to mount the subvolume that contains it.
For those of you who didn't understand much of the above, Btrfs offers better data protection than ext4, which is why Synology recommends you format the DS916+'s drives to Btrfs instead of ext4.