These operating systems will report less than 4 GB because of the memory used by add-in graphics cards and other system resources. NOTE When using a processor without Intel Graphics Technology, memory must be installed in either or both of the DIMM 0 (blue) memory sockets for the system to boot. Graphics Subsystem The board supports either integrated graphics (Intel Graphics Technology) or PCI Express 2.0 x16 graphics. Integrated Graphics The board supports integrated graphics through the Intel Flexible Display Interface (FDI) for processors with Intel Graphics Technology. Analog Display (VGA) The VGA port supports analog displays. The maximum supported resolution is 2048 x 1536 (QXGA) at a 75 Hz refresh rate. The VGA port is enabled for the POST whenever a monitor is attached, regardless of the HDMI and DVI connector status. Intel Desktop Board DH55HC Product Guide High-Definition Multimedia Interface* (HDMI*) The HDMI port supports standard, enhanced, or high-definition video, plus multichannel digital audio on a single cable. It is compatible with all ATSC and DVB HDTV standards and supports 8-channel digital audio. The maximum supported resolution is 1920 x 1200 at 60 Hz refresh (WUXGA). The HDMI port is compliant with the HDMI 1.3 specification. The HDMI port is enabled for the POST whenever a monitor is attached, regardless of the VGA and DVI connector status. Digital Visual Interface (DVI-D) The DVI-D port supports digital DVI displays. The maximum supported resolution is 1920 x 1200 at 60 Hz refresh (WUXGA). The DVI-D port is compliant with the DVI 1.0 specification. The DVI-D port is only enabled for POST when there are no monitors attached to the VGA or HDMI connectors. PCI Express* x16 Graphics The Intel Core i7, Intel Core i5, Intel Core i3, and Intel Pentium processors in an LGA1156 socket support discrete add-in graphics cards via the PCI Express 2.0 x16 add-in card connector. The board supports the following PCI Express speeds: • PCI Express GEN2 frequency of 2.5 GHz which results in 5.0 Gb/s in each direction (500 MB/s) per lane. The maximum theoretical bandwidth on the interface is 8 GB/s in each direction, simultaneously, when operating in x16 mode. • PCI Express GEN1 frequency of 1.25 GHz resulting in 2.5 Gb/s each direction (250 MB/s) per lane. The maximum theoretical bandwidth on the interface is 4 GB/s in each direction, simultaneously, when operating in x16 mode. Desktop Board Features Audio Subsystem The board supports Intel High Definition Audio through a Realtek ALC888S audio codec as well as through the HDMI interface. The Realtek ALC888S-based audio subsystem provides the following features: • Advanced jack sense for the back panel audio connectors that enables the audio codec to recognize the device that is connected to an audio port. The back panel audio connectors are capable of retasking according to the user’s definition, or can be automatically switched depending on the recognized device type. • Stereo input and output via back panel connectors • Headphone and Mic in functions for front panel audio connectors • A signal-to-noise (S/N) ratio of 90 dB The board provides onboard audio headers and back panel connectors. The onboard audio headers include the following: • Front panel audio (a 2 x 5 pin header that provides headphone and mic in signals for front panel audio connectors) • S/PDIF audio header (1 x 4 pin header) • Internal mono speaker header (1 x 2 pin header) Front panel headphone output is supported by a separate audio channel pair, allowing multi-streaming audio configurations such as simultaneous 6-channel (5.1) surround sound playback and stereo audio conferencing (through speakers connected to the back panel audio connectors and a headset connected to front panel audio connectors). The onboard internal mono speaker header allows connection to an internal, low- power speaker for basic system sound capability. The subsystem is capable of driving a target speaker load of 8 . at 1 W (rms) or 4 . at 1.5 W (rms). The onboard S/PDIF header allows connection to coaxial or optical adapters for digital audio output. The back panel audio connectors are configurable through the audio device drivers. Audio software and drivers are available from LAN Subsystem The LAN subsystem includes: • Intel 82578DC Gigabit (10/100/1000 Mb/s) Ethernet LAN controller • RJ-45 LAN connector with integrated status LEDs LAN software and drivers are available at Two LEDs are built into the RJ-45 LAN connector located on the back panel (see Figure 2). These LEDs indicate the status of the LAN as shown in Table 3. Intel Desktop Board DH55HC Product Guide Figure 2. LAN Connector LEDs Table 3. LAN Connector LEDs LED LED Color LED State Indicates A (Link/Activity) Green Off On Blinking LAN link is not established LAN link is established LAN activity is occurring B (Link Speed) N/A Off 10 Mb/s data rate Green On 100 Mb/s data rate ...