At around $900 with no storage included, Synology's DiskStation DS1511+ seems pricey at first. However, the more you get to know it, the more you realize it's worth every penny.
The DS1511+ is by far the best sub-$1,000 NAS server we've seen on all counts, including performance, design, hard-drive support, and even ease of use. Although it's probably not easy enough for home users, simply because it offers an overwhelming number of features that is far beyond what the uninitiated can expect. This doesn't mean the server is perfect, and Synology indeed could improve its setup process and the desktop software bundle. And of course it wouldn't hurt to lower the price, either.
If you know what you are doing and are serious about networking and network storage, look no further than the DiskStation DS1511+. If you want something with less storage, and cheaper, we'd also recommend the four-bay DS410 or the dual-bay DS710+.
Design and setup
The DiskStation DS1511+ is good-looking and is very compact for a server that supports five full-size 3.5-inch hard drives. In fact, it's about the same size as the four-bay DS410, and even less bulky-looking. The DS1511+ also beats the DS410 big-time in terms of hard-drive bay design: now you can service the hard drives without having to open the server's case. Each front-facing drive bay has a tray on which you can secure a hard drive with screws. The trays stay securely and firmly in place but can also be unlocked and taken out easily without any tools. This means hard drives can be replaced without turning off the server, as long as they are replaced one at a time.
The DS1511+ supports desktop SATA hard drives of any capacity, including the new 3TB hard drive. As a matter of fact, Synology DiskStations belong to a handful of NAS servers on the market that currently support hard drives that are larger than 2.19TB. This means the server can offer up to 15TB of storage before you have to resort to its peripheral ports.
Still, the server does come with plenty of ports: four USB 2.0 ports and two eSATA ports on the back. The eSATA ports can each be used to host an external hard drive or one Synology DX510 expansion unit. The DX510 can hold five hard drives and, according to Synology, once connected to the eSATA port, will offer the same throughput as the server's internal drive. This means, when used with two expansion units and 3TB hard drives, the DS1511+ can host up to 45TB of internal storage space.
The USB ports can also be used to connect more storage, or USB printers or uninterruptable power supplies (UPS). Unfortunately, the NAS doesn't support USB 3.0, which is much faster than USB 2.0. Nonetheless, with the support for a vast amount of internal storage, it will take a while, if at all, before you will need to add more via these ports.
Also on the back, you'll find two large ventilation fans, which manage to remain quiet during operation, and a power socket that takes the same type of power cable as a regular desktop computer. The DS1511+ has a built-in power supply so there's no need for a separate power adapter, as is the case with its predecessors, such as the DS410 or the DS710+.
The DS1511+ is the first NAS server from Synology we've reviewed to feature dual Ethernet. The server comes with two Gigabit Ethernet ports that can be used at the same time. By default these ports work together to balance out the workload to maintain the top speed of each port during heavy operation and serve as a failsafe in case one of the ports stops working. You can also switch them to work together in the Link Aggression mode to increase the total throughput speed but then can't take advantage of the failsafe function.
The DiskStation DS1511+ ships with no storage included and we tested our reviewed units with both 1TB and 3TB SATA hard drives. These drives can be set up in many RAID configurations, including the most desirable RAID 5 configuration, which requires at least three hard drives. RAID 5 gives a balanced combination of the most storage space and the best performance while still safeguarding the data from single-disk failure. What's better than RAID 5, however, is probably Synology's proprietary Hybrid RAID, which allows for using hard drives of different capacities as long as the replacement hard drive is of the same capacity as or larger than the one being replaced. This is similar to the XRAID 2 setup of the Netgear ReadyNAS Ultra 4 and makes it possible to upgrade the total capacity of the server without having to build the RAID setup from scratch. In our testing, Hybrid RAID offers the same performance as RAID 5.
Like other NAS servers from Synology, the DS1511+ won't pose any problem for savvy users when it comes to setup, but others may have more trouble. The server comes with a desktop application called Synology Assistant to help users with the initial setup. Apart from detecting the NAS and launching the Web interface, the software doesn't provide enough information on what it does and may be intimidating and confusing for those with little computer knowledge.
Unlike the desktop setup application, the server's Web interface, called DiskStation Manager, is one of the best. The server uses version 3.0 of the firmware. Once launched via a Web browser, all features and functions of the DS1511+ are listed in a well-organized menu on the left of the interface. Most of the setup sections are wizard-based and walk you through step-by-step. For example, at the home page of the Web interface, when we clicked on "Create User," a wizard launched to walk us through all the steps involved in making a new user and assigning that user's access to different share folders and so on. Most of all, the Web interface allows multitasking, meaning you can open multiple windows within the same Web page to manage different features at the same time. This makes the interface much like that of a standalone operating system.
We had no problem getting the server up and running. In our trial, the server took only about 30 minutes to switch from one RAID configuration to another. This is significantly quicker than most NAS servers, which take hours to get the same job done. This is because the DS1511+ allows you to skip the hard-drive check during a RAID build. This reduces the build time, but poses a potential problem if the hard drives contain bad sectors. When a disk check was included, the DS1511+'s RAID build time took about as long as any other NAS server. And this could mean days when you use all 3TB hard drives. In this case, it's better to build a Hybrid RAID starting with just one drive, then add more later. The server can still be used, though at a slower speed, while more drives are being added to the RAID.
Synology's NAS servers use the same DiskStation Manager firmware, also known as the operating system. This means most of them share the same features. In fact, the DS1511+ differentiates itself from the four-bay DS410, for example, only by supporting one more hard drive and up to 20 IP cameras (as opposed to 12).
Thus, you'll find this part of the review very similar to our review of the DS410.
The DS1511+ offers basically all the features you'd commonly see in a high-end NAS server, including the ability to work as an FTP/HTTP server, media streaming servers, support for user accounts, Active Directory, external hard drives, printer, iSCSI, and Time Machine backup for Macs.