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Analyzing the voltage regulator circuit (learn more about it on our Everything You Need to Know About the Motherboard Voltage Regulator Circuit tutorial) we can see that it uses ferrite chokes and solid aluminum capacitors. This motherboard uses a four-phase voltage regulator design, what is very good. By the way, all other electrolytic capacitors from this motherboard are Japanese from Sanyo.

 MA78GM-S2HFigure 5: Voltage regulator circuit.

Gigabyte MA78GM-S2H has four memory sockets, what clearly set it apart from other low-cost motherboards (which usually have only two memory sockets). It is compatible with DDR2 memories up to 800 MHz or 1,066 MHz, depending on the CPU, accepting up to 16 GB and also being compatible with dual channel architecture. It is important to note that on AMD CPUs the memory controller is embedded in the CPU, so who really defines memory compatibility is the CPU, not the motherboard or the chipset. So if you install a Phenom processor it will accept 1,066 MHz memories, but a Sempron or Athlon X2 will only recognize memories up to 800 MHz.Near the memory sockets you will find one ATA-133 port, the floppy disk drive connector and a parallel port header (you need an I/O bracket to use the parallel port, which doesn’t come with this motherboard), see Figure 6.

 MA78GM-S2HFigure 6: Memory sockets.

Near the south bridge chip (which is cooled by a small passive heatsink) you will find five SATA-300 ports, which can work under RAID 0, 1, 10 or JBOD modes. Not bad at all, an HTPC computer will hardly need more than that.

The RD700 south bridge chip supports 12 USB 2.0 ports and on this motherboard only four are located on the rear panel, what is a pity. The eight remaining ports are available on headers that require I/O brackets or adapters to be used. Even if you install memory card readers, the USB ports from the case, etc you will still have too many unused USB ports. We would like to see at least six USB ports on this board’s rear panel.

The connectors for the computer case (on/off and reset switches, LED’s, etc) aren’t colored but can be very easily identified thanks to a very well printed silk-screen layer on the printed circuit board.

 MA78GM-S2HFigure 7: South bridge, SATA ports and eight USB headers (two ports per header).

Gigabyte MA78GM-S2H has two PCI slots, one x1 PCI Express slot and one x16 PCI Express slot, where you can install a “real” video card. If your video card is based on an ATI chip and compatible with the “Hybrid CrossFire” mode you can enable it in order to increase gaming performance. Under this mode the on-board video works in parallel with the add-on video card increasing performance, but only a very few low-end video cards are compatible with this mode. Read our SLI vs. CrossFire article for a list of compatible cards.

In Figure 8, you can see, besides these slots, the passive heatsink (i.e., without a fan) from the north bridge chip. This heatsink is cut in a way to allow the installation of long cards in the x1 PCI Express slot or of a video card with a heatsink on its backside. Unfortunately this heatsink works extremely hot all the time and Gigabyte could have done a better job and added a heatsink with a better performance to make the north bridge chip to work a little bit cooler.

MA78GM-S2HFigure 8: Expansion slots.

But it is on its rear panel that MA78GM-S2H shows that it isn’t a low-end motherboard. Even though it doesn’t have serial and parallel ports (they are available on the motherboard through headers, requiring the use of I/O brackets that you can buy separately if you want to use them) this panel has several features targeted to HTPC’s.Besides the mouse and keyboard PS/2 connectors you can see three different video outputs: VGA, DVI and HDMI (supporting digital audio). You can’t use the three of them at the same time, however, only two. This is the first time we’ve seen a motherboard with these three video outputs at the same time. This motherboard also has an optical SPDIF output (a mandatory feature on HTPC’s), four USB 2.0 ports, one FireWire port and one eSATA-300 port (which supports RAID with the internal SATA ports). As we have already mentioned, we’d like to see more USB ports here. You will also find a Gigabit Ethernet port and full 7.1 analog audio independent outputs.

MA78GM-S2HFigure 9: Rear panel.

Together with the on-board HDMI connector the highlight of this motherboard is its on-board audio, using a high-end Realtek ALC889A codec, a rarity even on high-end products. One constant complaint we make regarding on-board audio solutions is the low signal-to-noise ratio (SNR) for the analog input. With values below 95 dB you will have a lot of white noise (background noise) when converting analog audio sources to digital format (VHS to DVD or other digital format, LP to CD or MP3, etc). This codec, however, offers a signal-to-noise ratio on the same level of professional add-on sound cards: 104 dB for its analog inputs and 108 dB for its analog outputs. You can use this motherboard to build a PC to work professionally with audio and video editing without the need of an add-on sound card. The on-board optical SPDIF connector completes the package.


Rafael Otto Coelho is a physicist with a master’s degree in Education, and is a college professor in Brazil.