Most new PCs have HDMI ports for outputting high-definition video to HDTVs, but just a couple of years ago that wasn’t the case--and if you want to watch high-def content (for example, anything you buy on iTunes) on a big screen, getting it to that screen isn’t easy. The Cirago USB to HDMI Display Adapter solves the problem by turning your HDTV (or any other display that accepts HDMI input) into a second monitor that connects to your PC through a USB 2.0 port instead of a graphics card.
Not only is this approach relatively inexpensive--the adapter costs $60 (as of November 5, 2011)--but it also circumvents the hassles that can arise with alternatives, such as streaming to a set-top box via a wireless or wired home network. The ability to send material via a USB port can also benefit businesses that want to connect multiple displays or a projector to a single computer.
However, the video quality isn’t always perfect because of the compression required to meet the bandwidth limitations of USB 2.0. The compression algorithm is part of the DisplayLink technology on which the Cirago device is based. DisplayLink was created to support the use of USB ports for easy display hookups.
Smaller than a deck of cards, the Cirago HDMI to USB Adapter accepts the smaller end of a standard USB cable (Cirago includes one in the package) on one side, and an HDMI cable (not included) on the other. Cirago also tosses in an HDMI-to-DVI adapter for those users who need support for DVI, the video-only predecessor of HDMI.
The device draws power from the USB connection, so it requires no other hookup. Once I plugged the larger end of the USB cable into a Windows 7 PC, drivers and software to manage the device installed automatically. (Drivers for earlier versions of Windows and for the Mac OS are available on an included CD.)
The driver basically creates a virtual second monitor that appears in a drop-down list on the page for adjusting display properties in Windows. You can opt to extend your desktop to the second monitor (the HDTV), to mirror the desktop, or to view either the original display or the second monitor only.
You can make further refinements using the DisplayLink software, which you access from the Windows 7 taskbar (where it appears as an icon). Its two main features are 'Fit to TV' and 'Optimize for Video'. For watching PC content on my TV, I made it my primary desktop and clicked the 'Fit to TV' command, which scaled my Windows 7 desktop to fit the set’s screen. If you don’t like the default dimensions (which worked perfectly with my 1080p Panasonic plasma), you can adjust the height and width of the desktop using buttons in the DisplayLink app.
The 'Optimize for Video' command is supposed to improve video quality within the constraints of USB’s bandwidth. In my tests watching TV programs in iTunes, the video and audio sometimes froze briefly, especially when I first started the programs. I also noticed that the image on the TV set did not retain the crispness and clarity of the PC video, presumably because of the DisplayLink compression. However, the device did automatically send the audio stream with the video, so I didn’t have to take extra steps to play the audio through my TV and not my PC.
Overall, the Cirago USB to HDMI Adapter is a quick and inexpensive tool for people who want to enjoy PC content on a big-screen HDTV--but only if you’re willing to live with the somewhat inferior image quality introduced by DisplayLink compression.