PCB Design and Functionality
The Biostar TZ68K+ doesn’t seem to differ from others at first sight, but you can spot a number of peculiarities on closer inspection.
First off, we’re dealing with the senior model of the series. Compared to the junior TZ68A+, it features an eight-phase CPU voltage regulator. The hot components of the latter are equipped with small heatsinks which are secured with spring-loaded plastic locks, just like the chipset heatsink. The mainboard doesn’t employ additional disk controllers and only offers two SATA 6 Gbit/s (white connectors) and four SATA 3 Gbit/s (red connectors) ports which are supported by the Z68 Express. The expansion opportunities are limited to two PCI slots, one PCI Express 2.0 x1 and two PCI Express 2.0 x16 slots. Although the chipset allows splitting its 16 PCIe lanes into two 8-lane groups, the mainboard doesn't utilize this. As a result, the first graphics slot always works in full-speed PCIe x16 mode whereas the second one is allotted but four PCIe lanes. You can join two graphics cards into an AMD CrossFireX subsystem whereas Nvidia's SLI technology is not supported.
Besides a COM port, which is quite a rare thing to see on a modern mainboard, the Biostar TZ68K+ even offers an LPT one. There are Power and Reset buttons in the bottom right corner but they are identical and not highlighted, so you may easily get confused. Next to the buttons you can see two Rapid Debug LEDs which may help you diagnose startup-related problems. If the mainboard starts up normally, both LEDs are alight. If only the first one is alight, the problem is in your memory modules. If you only see the second LED shining, it’s a graphics card problem. If the LEDs do not shine at all, it’s the CPU or the mainboard itself.
We haven’t seen anything unusual so far, but let’s take a look at the mainboard’s back panel.
The short list of the back-panel connectors includes the following:
- PS/2 keyboard connector;
- Only two USB 2.0 ports, six more are laid out as three onboard pin-connectors, but there are no brackets with additional USB ports for the system case back panel;
- HDMI, DVI and D-Sub video outs distributed evenly over the entire back panel;
- A local network port (network adapter is built around Gigabit Realtek RTL8111E controller);
- Two USB 3.0 ports (blue connectors) implemented via ASMedia ASM1042 controller;
- Only three analogue audio-jacks provided by eight-channel Realtek ALC892 codec.
Well, even Gigabyte’s mainboards do not make full use of their back panels nowadays, but it's been a long time since we last saw a mainboard's back with so few components on it. We haven't minded Biostar's attempts at cutting its costs so far, but would it really be that costly to put at least two (or, better, four) USB ports there? And if not a cost-cutting measure, why does the mainboard’s back panel look so bleak?
The following table summarizes the key specs of the Biostar TZ68K+ mainboard:
There is a Power Indicator label along the top edge of the mainboard but we couldn't find a line of LEDs that would report the number of active power phases in the CPU voltage regulator. The mainboard has only three connectors for fans. The CPU fan connector is the only one that can regulate the speed of the connected fan but only if the latter uses 4-pin connection. Overall, we can't find any serious flaws in the mainboard's design except that the first graphics slot is too close to the CPU socket which makes it difficult to change memory modules with the graphics card installed or even removing the graphics card itself if you’ve got a large CPU cooler. We can put up with that, though. The main problem is the limited number of connectors available on the mainboard's back panel.