Gigabyte C847N Motherboard
By Rafael Otto Coelho on May 23, 2013
The Gigabyte GA-C847N is a Mini-ITX motherboard with a soldered Celeron 847 CPU. It uses the Intel NM70 chipset and has one PCI slot. Let’s take a look at this little board.
The Celeron 847 is derived from the mobile version of the second generation Core i3 (Sandy Bridge) CPU, aimed at low-cost laptops. Its nominal clock is 1.1 GHz and it has 2 MiB of L3 memory cache. The main difference to a mobile Core i3 processor is the lack of the Hyper-Threading technology. It also has a smaller amount of L3 memory cache, since second-generation Core i3 mobile CPUs have an L3 memory cache of 3 MiB.
The NM70 chipset, despite its name (that looks like an Atom family chipset), is a low TDP version of the HM75 chipset.
You can see the Gigabyte C847N motherboard in Figure 1.
Mini-ITX motherboards have only one expansion slot. Gigabyte builds the C847N with a standard PCI slot instead of using a PCI Express one, which is a clue that the motherboard is not aimed at multimedia or HTPC applications, but at low-cost sales terminals, kiosks, and other business applications PCs.
It’s a shame that Gigabyte did not put a Mini PCI Express slot, which could be used to install a Wi-Fi adapter.
Currently, Intel CPUs have an embedded memory controller, meaning that it is the processor, not the chipset, that defines what memory technologies you can have and the maximum amount of memory that is possible. The motherboard, however, may have a limitation as to how much memory can be installed.
The integrated memory controller of the Celeron 847 CPU supports DDR3 memories up to 1,333 MHz. According to Gigabyte, the C847N is limited to memories up to 1,333 MHz.
The motherboard has two memory sockets, supporting up to 16 GiB if you use two 8 GiB modules.
In order to enable the dual-channel mode and achieve the highest performance possible with this motherboard, you must install two memory modules.
The Intel NM70 chipset is a single-chip solution, which is known as a PCH (Platform Controller Hub). This chip has three SATA-300 ports and only one SATA-600 port, with no RAID support. The GA-C847N is equipped with those four ports, but one of the SATA-300 ports is located at the rear panel of the motherboard, as an eSATA port.
The portrayed motherboard also has one ATA-133 port, controlled by a JMicron JMB368 chip, supporting up to two parallel ATA devices. We couldn’t determine the point of having an ATA-133 connector nowadays.
The NM70 chipset supports eight USB 2.0 ports. The GA-C847N offers all those ports, four located on the rear panel and four available through two headers located on the motherboard. There are no USB 3.0 ports, which is a big drawback. There are no FireWire ports, either.
This motherboard supports 7.1 audio format using a Realtek ALC887 codec. This codec has the same specifications as the Realtek ALC892, except that the ALC892 has two extra channels for audio streaming. The main specifications of this codec include 97 dB signal-to-noise ratio for the analog outputs, 90 dB signal-to-noise ratio for the analog inputs, and up to 192 kHz sampling rate for both inputs and outputs, with 24-bit resolution. These specs are good for the mainstream user, but if you are looking into working professionally with audio editing, you should look for a motherboard that provides an SNR of at least 97 dB for the analog inputs.
The analog outputs are shared, meaning that if you want to use a 5.1 analog speaker set (7.1 audio is only available if you install a front panel HD audio module), you will have to use the “Line In” and “Mic In” jacks, and they won’t be available for their original uses. The motherboard doesn’t have optical or coaxial SPDIF outputs. Those drawbacks disqualify the Gigabyte C847N for HTPC applications.
The portrayed motherboard has two Gigabit Ethernet ports, controlled by two Realtek 8111F chips. This could be interesting in small server, NAS, or firewall applications.
The Gigabyte C847N has two legacy serial ports, one available at the rear panel of the motherboard, and one available through a header on the motherboard. There is also a parallel port available through a header on the motherboard, but the adapters to use these headers don’t come with the motherboard.
In Figure 5, you can see the rear panel of the motherboard with PS/2 connectors for keyboard and mouse, VGA output, a legacy serial port, an eSATA port, an HDMI output, four USB 2.0 ports, two Gigabit Ethernet ports, and the analog audio jacks.
Figure 6 shows the cooler installed on the Celeron 847 CPU, while Figure 7 reveals the processor without the cooler. The three-phase voltage regulator is enough for this low-consumption CPU. All the capacitors are solid, and all the coils are ferrite ones, which is great.
The Gigabyte C847N doesn’t bring any overclocking options.
In Figure 8, you can see all of the accessories that come with the Gigabyte C847N.
The main specifications for the Gigabyte GA-C847N include:
* Researched at Newegg.com on the day we published this review.
Most Mini-ITX motherboards are aimed at SFF multimedia PCs or HTPCs. This is not the purpose of the Gigabyte C847N, because it lacks decent audio interface, with no SPDIF output nor independent analog audio connectors. The absence of USB 3.0 ports are also a huge drawback nowadays.
However, the highlight of the GA-C847N is how inexpensive it is. It would be a great choice to build a low-cost, compact PC to act as a sales or customer terminal, a kiosk, an office computer, and also dedicated applications such as a small server, router, firewall etc. The fact that it uses a low consumption CPU is also welcome in all those applications.