The images to the right show the Intel Atom N455-powered Advantech ARK-DS520 from the front and back. In terms of I/O, the player provides:

• 4 x USB 2.0 (two front, two back)

• 2 x Serial RS232

• Digital I/O

• Audio Microphone

• Audio Line-Out

• 2 x RJ-45 gigabit LAN

• Power (12 Volt DC)

• HDMI (up to 1080p)

• 2 x VGA Video (up to 2048 x 1536)

• DVI-D Video (up to 1600 x 1200)

The images to the right show the DS520 from the left and right side, each with an access door. The door panel on one side provides access to the unit's CF Card Type II slot, which is used for systems running off Flash (Advantech sells versions with 4, 8, or 16GB of industrial-grade CF Flash).

The review ARK-DS520 Advantech sent us included a 2.5-inch Seagate Momentus ST9160314AS hard disk with a 3Gb/second SATA interface and a capacity of 160GB. The disk sits in a separate, shock-mounted caddy enclosure underneath the system board. It's spinning at 5,400 RPM and is quite power-efficient, using about 1.4 watts idling and about 1.8 watts operating. The disk's operating temperature range is 32 to 140 degrees Fahrenheit and it can handle operating shocks up to 350Gs. While the DS520 can run off Flash, many signage applications may require the much greater storage space provided by a conventional hard disk.

Below to the right you can see what the DS520 system board looks like from the top and the bottom:

The motherboard itself, essentially an embedded single board computer, measures 8.0 x 5.7 inches and includes the CF Card Type II slot. All I/O connectors are edge-mounted directly on the board, and all other expansion card slots are also directly on the board.

On the topside, you can see, moving from left to right, one of the two full-size PCIe slots, the large (31 x 31mm package) Intel ICH8 chip, the small NVIDIA GT218 ION2 chip with its four memory chips, below that the Intel Atom N455 processor, and to the right of that the board's two DDR3 204-pin DIMM slots (populated in our tester by a single 2GB module).

What you don't see is a CPU fan, and that's because the processor, chipset and graphics engine as well as the dedicated onboard display memory and the SODIMM memory module all make contact with the finned aluminum heatsink and dissipate heat that way (a qualification here: systems equipped with the D525 dual-core CPU do have a fan).

On the bottom side of the system board you can see the black edge connector for the hard disk caddy, the white CF Card connector, the second PCI-e slot, which is also full sized, and beneath it a SIM Card slot.

The SIM Card slot wasn't actually listed in the specs, but combined with a WiFi or radio PCIe module, the DS520 obviously can be equipped with wireless data connectivity (or just with WiFi). The PCI-e slots can also be used for adding a TV tuner module or similar extra functionality.

As we've come to expect from the major embedded systems manufacturers, the system board is very clean and totally devoid of any fixes or components that look like they might break off or rattle loose.

NVIDIA ION2 graphics

Because the graphics that come with the Atom processor and chipset can't really handle the high graphics demands of a modern digital signage player. Millions of Atom-based netbook users found out they really couldn't run high definition video at an acceptable frame rate. In an earlier Advantech digital signage player we reviewed, the ARK-DS303, Advantech handled the problem with an optional PCIe Broadcom "Crystal HD" hardware accelerator module using the Broadcom AVC/MPEG-2/VC-1 video/audio BCM70010/BCM70012 decoder chipset. With the DS520, they went a different route and chose a fully integrated third party graphics solution with the ION2.

The purpose of NVIDIA ION2 graphics is to provide much better graphics performance for advanced applications than the standard processor-integrated graphics can. In consumer notebooks that meant the ability to play complex games, in netbooks being able to watch full 1080p HD video, and in digital signage the ability to power multiple video streams at acceptable speed. ION2 refers to the second generation of the ION platform which, in contrast to the first generation, is just a GPU and not an entire chipset. As such, it works in conjunction with the Intel Atom "Pine Trail" platform used in the ARK-DS520 (as well as in millions of second and third gen netbooks). See NVIDIA's ION page with a demo video here.

In its documentation, Advantech claims over 10 times normal performance in media playback with the ION2 and NVIDIA Optimus technology.

To see how the ION2-based ARK-DS520 compares to the value-positioned ARK-DS303 with the Broadcomm module we ran our standard PassMark and CrystalMark benchmark suites. To illustrate how these devices with their tweaked graphics compare with Atom boards running standard Intel graphics, we included the test results of the Advantech SOM-6760 and SOM-5761 (see comparison here), two COM-Express boards running first-gen Atom chips. The results are as follows:

BENCHMARK PERFORMANCE	ARK-DS520	ARK-DS303	SOM-6760	SOM-5761
Device Type	Signage Player	Signage Player	COM-Micro	COM-Express
Processor	1.66GHz Atom N455	1.6GHz Atom N270	1.6GHz Atom Z530	1.6GHz Atom N270
TDP	6.5 watts	2.5 watts	2.3 watts	2.5 watts
Graphics	NVIDIA ION2	Broadcomm	Intel	Intel
CPU Mark	248.7	252.6	315.6	321.1
2D Graphics Mark	71.3	158.7	207.2	192.5
Memory Mark	220.4	227.7	191.6	199.1
Disk Mark	445.9	459.4	70.7	74.6
3D Graphics Mark	169.1	77.3	19.6	71.5
Overall PassMark	226.3	232.6	137.3	190.7
CPU Alu	6,296	5,409	5,376	5,413
CPU FPU	4,033	4,671	4,667	4,726
Memory	6,033	4,223	3,667	4,172
HDD	7,827	8,221	2,702	2,676
GDI	2,302	2,158	2,427	2,239
D2D (Sprites)	2,936	2,230	1,009	2,180
OpenGL	5,183	684	505	704
Overall CrystalMark 2004R2	34,610	27,596	20,353	22,110
Playback 1280x720 (720p) HD movie in QuickTime	Flawless	Flawless	4-5 fps (choppy)	8-10 fps (choppy)

As is usually the case with benchmarks, the results are both interesting and a bit confusing. For example, the original Z5xx Series of Atom processors always benchmarked poorly in 3D tasks, though their subjective performance seemed no worse than that of the N2xx Series used in netbooks.

As far as the DS520 goes, the CrystalMark showed very good 2D performance and the PassMark 3D performance score is excellent. The PassMark 2D graphics score is unexpectedly low even compared to a standard N270 board, though subjectively the DS520 performed at least at the N270 level. Where the ION2 implementation really shines is in OpenGL, the cross-platform API widely used in complex information visualization, simulations and games. In the CrystalMark OpenGL benchmark, the DS520 easily outperformed even Intel Core I5/i7-based systems. Nothing without discrete graphics comes even close.

We didn't have a benchmark for HD encoding and decoding, but subjectively, the DS520 (like the DS303) provided flawless 720p and 1080p playback, something older Z530 and N270-based systems definitely couldn't.

Dual-screen support and applications

For display settings and configurations, the ARK-DS520 comes with a special NVIDIA control panel that provides precise control over each attached display (see below).

Note that Advantech also offers a TV tuner module so that TV programing can be included when real-time news or entertainment is crucial. CEC (Consumer Electronics Control) is implemented on HDMI and that can potentially be used to control up to ten CEC-enabled devices.

Ruggedness and utilities

Unlike consumer-grade, off-the-shelf media players, the Advantech ARK-DS520 is expected to run 24/7 all the time, with minimal maintenance requirements. That's why it is not only built like a tank, but also comes with special BIOS settings for digital signage applications, such as system Wake-on-LAN and Power-On-after-Power-Failure settings. There is also an embedded watchdog timer that allows for near 100% uptime, and there are additional functions that help the system recover from fatal errors or system crashes.

The system also includes a number of special Advantech utilities:

• The Advantech Booting Manager lets developers turn off a variety of Windows-specific logos and screens. So instead of booting up like a standard PC, a digital signage may simply boot directly into its custom software, without any Windows logo, logins, sounds, and so on.

• The Enhanced Write Filter, or EWF, is a security feature that lets you write-protect a run-time image by redirecting write operations to another storage location, thus preventing any damage that might be caused by an unexpected power failure, vibration or even a virus attack.

• FBWF, the "File Based Write Filter," lets embedded systems developers quickly prototype and integrate file-based write filters. FBWF is used to provide the appearance of read and write access to write-sensitive or read-only storage and makes read and write access transparent to applications. What FBWF does is write to a cache instead of media that is not supposed to be altered or written on. As such, FBWF acts a bit like EWF, but it's more powerful and there are more features.

Bottom line

Designed and manufactured as an industrial-class device, the DS520 is for digital signage/kiosk projects where requirements include maximum life expectancy even under 24/7 operation, the ability to handle wide temperature ranges, a long product life cycle, and, thanks to the NVIDIA ION2 GPU, the ability to play high definition content on a low cost, low power Atom-based device. In our review and testing, the light and compact ARK-DS520 convinced with extremely solid construction and very good performance.

Customers will have to decide between the fanless single-core Intel Atom N455 version (US$730) and the only slightly more expensive dual-core Intel Atom D525 version (US$750) that does have a fan. -- Conrad H. Blickenstorfer, May 2012

Advantech ARK-DS520 Digital Signage Player Specs: