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Synology DiskStation DS1511+ review: Synology DiskStation DS1511+

Synology DiskStation DS1511+

Dong Ngo SF Labs Manager, Editor / Reviews
CNET editor Dong Ngo has been involved with technology since 2000, starting with testing gadgets and writing code for CNET Labs' benchmarks. He now manages CNET San Francisco Labs, reviews 3D printers, networking/storage devices, and also writes about other topics from online security to new gadgets and how technology impacts the life of people around the world.
Dong Ngo
11 min read

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.


Synology DiskStation DS1511+

The Good

The Synology DiskStation DS1511+ offers fast throughput speed, excellent hard-drive bay design, top storage capacity, an overwhelming number of features, dual Gigabit Ethernet, multiple peripheral ports, and a state-of-the-art Web interface. The server handles both standard RAID configurations and flexible Hybrid RAID, and supports up to 20 IP cameras.

The Bad

The Synology DiskStation DS1511+ doesn't support USB 3.0 and its setup application is not straightforward enough. It includes only one IP camera license and is comparatively pricey.

The Bottom Line

The DiskStation DS1511+ is arguably the best five-bay NAS server on the market for both home and office environments. Novice and home users, however, might be intimidated by its setup software and the number of features it has to offer.

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.

On top of that, the DS1511+ has features that you're unlikely to find in others, organized in a set of "stations," such as Surveillance Station, Download Station, File Station, and Photo Station. All of these stations can be accessed via the local network or over the Internet. Some of them also come with mobile applications for the iPhone or iPod Touch or Android-based smartphones.

The following, by the way, are just a few noticeable features of the DS1511+ that we have tried out and were impressed by. The server offers a lot more, but it would make this already long review much longer to talk about all of them.

The DS1511+'s Surveillance Station supports up to 20 IP cameras. This means you can use the NAS server as a video recorder and managing station of a very comprehensive surveillance system. Unfortunately, only one camera license is included, and additional camera licenses cost $49 each. Other than that, this feature worked really well in our trial. We could view live images and record them based on scheduling or motion detection. When multiple cameras were used, we could even synchronize the playback to see what was recorded by different cameras at a given time. The server supports a long list of IP cameras and is able to automatically detect those connected to the local network to help facilitate the setup process. Synology also offers an app called DSCam for both the iPhone and Android devices, so you can manage your surveillance via your mobile device even when you're out and about.

The DS1511+'s Photo Station allows you to easily organize photos into albums. Once activated, a share folder called "photo" will be created. Photos stored in this share folder will be automatically placed in well-organized, customizable albums, one for each subfolder. You can then browse the album via a Web browser, as with Google's Picasa Web albums, and very easily add captions and comments to each photo. The Photo Station also offers a complete blogging engine for those who want to chronicle their lives with both photos and texts. The Photo Station includes a mobile app called DS Photo for the iPhone and Android platforms. The Photo Station has a separate set of user accounts from those of the NAS server. This allows the owner to share photos and blogs with others without compromising the security of other types of data and services on the server.

The Download Station allows the server to download files from the Internet by itself and is able to download files from Web sites that require authentication (such as RapidShare). It also supports the eMule and BitTorrent file-sharing services. You can manage your download any time from anywhere via the local network or the Internet by accessing the server's Web interface. This is an excellent feature for those who want to download large files, as no other computer needs to be running, other than the NAS server itself, during the downloads.

We did find a few things that could be improved about the Download Station, however. First of all, other than RapidShare, Megaupload and BitTorrent, the station doesn't remember usernames and passwords for any other download services or Web sites. This means if you download a lot from some other Web site that requires authentication, you'll need to manually enter the credentials for each download, which can be a hassle. The second issue is that its Download Redirector desktop software, which allows you to manage downloads from a computer instead of having to log in the server's Web interface, doesn't work over the Internet, but just from within the local network. As many other features, such as the Surveillance Station, can work over the Internet, we don't see why this would not be available for the Download Station. These are minor shortcomings, however; the way it is right now, the Download Station is still one of the best offered on an NAS server.

Any local computers, Mac or PC, can access the DS1511+'s storage via its share folder, similar to browsing for shared data between computers. However, if you want to access the server's storage via the Internet, you'll need to use its File Station. To do this, you'll need to know how to set up a dynamic domain name system (DDNS) connection or access the Internet via a static IP. The DS1511+ made it a little easier for users by adding the ability to automatically change the settings of the router if it supports UPnP. Still, the process is not easy and intuitive enough for those with little networking know-how. Once set up, the File Station enables you to access data in the NAS server's share folder over the Internet. You can download a single file or a whole folder to the remote computer and can upload files or a whole folder to the NAS server. Multiple users can use this feature at once from different locations.

The DS1511+ has built-in backup options that are focused on backing up its content onto an external storage device or a network location. For backing up files on your computer to the DS1511+, there's the Data Replicator desktop software. This is a simple, straightforward backup application that allows you to quickly copy data, much like copying and pasting using Windows Explorer, from your computer to the DS1511+. Also, the software has a nice feature that helps you find and quickly back up e-mail archives, which generally are buried deep in layers of subfolders within a user profile. In addition, it allows scheduling and keeping track of the backup process via e-mail notification. However, we found that the software is a little buggy at times and might kick you out of some applications, such as a game, when the backup process starts.

We tested the DS1511+ with its Hybrid RAID and RAID 0, and the server's performance was stellar via Gigabit Ethernet, even with with Link Aggression turned off.

In Hybrid RAID, which is similar to RAID 5, the server scored 99.21MBps and 109.89MBps in write and read, respectively. These are about the same speeds as a USB 3.0 external hard drive, and even faster than some. The server did even better in RAID 0, which is optimized for performance at the expense of data integrity, with 104.9MBps write and 112.28MBps read.

It was also interesting that the writing performance and reading performance of the DS1511+ are similar. For most NAS servers, the write speed is significantly lower than the read speed.

All in all, we were very happy with the DS1511+'s performance. It was consistently the fastest we've reviewed. The server also performed quietly in our labs, where there is a rather high level of ambient noise. In a quiet room, you might hear the subtle humming of the ventilation fans.

CNET Labs NAS performance scores (in MBps)
(Longer bars indicate better performance)
Synology DiskStation DS1511+ (Hybrid RAID)
QNAP TS-259 Pro (RAID 1)

Service and support
As with other NAS servers it has released, Synology backs the DS1511+ with a three-year warranty from the date of purchase, which is one year longer than for the DS410. Phone tech support is available Monday through Friday 9 a.m. to 5 p.m. PT. At its Web site, you can find Synology's forum, download software, and the latest firmware, and get more information about its products from its Wiki page.


Synology DiskStation DS1511+

Score Breakdown

Setup 8Features 9Performance 9Support 8