PCB Design and Functionality
By looking at the picture of the Intel DZ77BH-55K mainboard we can easily see that all our suspicions about its “awkward” layout were totally unjustified. The board looks perfectly fine and normal, its layout is close to the classical design and therefore we can hardly come up with any complaints.
The first thing I would like to point out is the fact that this mainboard supports all contemporary LGA 1155 processors. It is hard to say definitively what exactly the promised optimization for K-series processors implies, but there is no reason for us not to trust the developers on this one. The components of the processor voltage regulator circuitry that may heat up during work are covered with two additional heatsinks. All heatsinks including the third one on the chipset are held in place with plastic push-pins with springs. However, we won’t mark it as a shortcoming, because the heatsinks barely get warm. In the memory sub-system design there are also no differences from the “Extreme” series mainboards. The board has four DDR3 DIMM slots that can accommodate up to 32 GB of RAM. For Ivy Bridge processors the supported memory frequency range in the BIOS goes from 1066 to 2666 MHz.
For expansion cards there are two PCI, three PCI Express 2.0 x1 and two PCI Express 3.0/2.0 x16 slots, which share 16 PCI-E lanes and support AMD CrossFireX and Nvidia SLI graphics configurations. Besides two SATA 6 Gbps ports (blue connectors) implemented in the chipset, there are two more SATA 6 Gbps ports (gray connectors) implemented via Marvell 88SE9172 onboard controller. Out of four SATA 3 Gbps ports provided by the Intel Z77 Express chipset, there are only three connectors on the PCB (black connectors). Two of them are right next to all other connectors, one above the other, and the third one is a little farther away from them next to the 24-pin power connector. The fourth chipset port is implemented as an eSATA 3 Gbps on the back panel.
Two video outs, HDMI and DisplayPort, are more than enough for a mainboard that will most likely be sued with at least one graphics card, and maybe even two. The back panel layout is not very optimal and there is a lot of free space. However, the absence of numerous video outs, which will hardly be utilized anyway, allowed the engineers to bring there a lot of other ports and connectors. overall, the Intel DZ77BH-55K backpanel looks as follows:
- Universal PS/2 connector for keyboard or mouse;
- Four USB 2.0 ports, two of which are High Current ports for charging external devices (yellow connectors), another six ports are laid out as three onboard pin-connectors;
- Glowing “Back to BIOS” button;
- Four USB 3.0 ports (blue connectors) implemented using the Intel Z77 Express chipset functionality, and an internal pin-connector for two more USB 3.0 ports laid out using NEC/Renesas D720200AF1 controller;
- IEEE1394 (FireWire) port implemented via Texas Instruments TSB43AB22A controller, a second port is available as an onboard pin-connector;
- eSATA 3 Gbps port implemented due to Intel Z77 Express chipset functionality;
- Local network port (network adapters are built on Gigabit Intel WG82579V network controller);
- Optical S/PDIF and five analogue audio-jacks provided by eight-channel Realtek ALC898 codec.
The components layout allows us to notice a few additional features, which make working with the board even easier. Among them are a glowing Power On button and a POST-code indicator. A little above the top heatsink we see a row of VR Status LEDs, which should indicate the number of active phases in the processor voltage regulator circuitry. The first LED stands for the drives activity, the next two signal if the processor or its voltage regulator get overheated, and the rest of them light up one by one as we go through the start-up procedure indicating initialization of the processor, memory, graphics card, etc.
Just like the two previously discussed higher-end mainboards, the only shortcomings Intel DZ77BH-55K has are not the best location of the internal USB 3.0 connector at the very bottom of the PCB and the missing option to turn off the speaker. The former is not really a big deal in this case. “Extreme” mainboards are bundled with an additional module with two USB 3.0 ports, and what was originally intended as an advantage may actually turn into a frustrating issue if the cable is not long enough to allow installing this module into the empty 3-inch system case bay. Since there is no module like that with the Intel DZ77BH-55K mainboard, you may find one with the long enough cable yourself, or use the ports integrated into the system case, if you have a relatively new one. As for the second shortcoming, the mainboard now play Intel’s standard music theme on start-up, which you may have heard many times before in Intel commercials. The problem is not that much the poor sound quality, but the fact that sometimes the boards freak out and they keep playing this tune without stopping over and over again. This questionable feature may be disabled in the BIOS, which we did right away, but in this case the board will beep loudly upon start-up, which may also be unacceptable. Unfortunately, there is no parameter that would allow us to turn off all start-up sounds completely.