Let’s take a look at a mainstream socket AM3 motherboard from ASUS based on AMD790X chipset with SB750 southbridge (and thus supporting ACC feature, that allows you to unlock hidden features on selected Phenom CPUs), M4A79XTD EVO.
ACC (Advanced Clock Calibration) present on SB750 south bridge chip allows you to unlock hidden features from certain Phenom processors: depending on the CPU model you can unlock extra memory cache and even one extra CPU core, in the case of triple-core CPUs. You can read more about this feature here and here. As mentioned this feature is supported on this motherboard.
Keep in mind that socket AM3 motherboards are compatible only with socket AM3 CPUs. While socket AM3 CPUs can only be installed on socket AM2+ motherboards, you cannot install socket AM2+ CPUs on socket AM3 motherboards. In fact AMD says that this installation will burn the CPU and the warranty doesn’t cover this situation.
The first thing we noticed on M4A79XTD EVO is the presence of only solid capacitors and the different design from the heatsinks.
[nextpage title=”Slots and Memory”]
ASUS M4A79XTD EVO motherboard comes with two x16 PCI Express 2.0 slots, two PCI Express x1 slots and two standard PCI slots. When only one video card is used, the main PCI Express x16 slot (blue) really works at x16, but when two video cards are installed both slots work at x8.
Socket AM3 CPUs support both DDR2 and DDR3 memories, but the kind of memory you can have depends on the kind of motherboard they are installed on, socket AM2+ or socket AM3, respectively. Being a socket AM3 motherboard, ASUS M4A79XTD EVO supports only DDR3 memories. It comes with four memory sockets and in order to achieve the maximum performance possible you need to install two or four memory modules in order to enable the dual channel feature, which doubles the available memory bandwidth. If two modules are used, you need to install them on sockets with the same color. On this motherboard sockets one and two are black and sockets three and four are blue.
The maximum amount of memory you can have is 16 GB (by using four 4 GB modules) and although officially socket AM3 CPUs support up to DDR3-1600/PC3-12800 modules, ASUS M4A79XTD EVO supports up to DDR3-1800 memories through overclocking.
[nextpage title=”On-Board Peripherals”]
SB750 south bridge chip supports six SATA-300 ports allowing RAID 0, 1, 5, 10 and JBOD, and one ATA-133 port. ASUS M4A79XTD EVO comes with an extra chip from Marvell that brings one extra SATA-300 port (the one that is black on the motherboard) and one eSATA-300 port on the rear panel.
All the SATA ports are located on the corner of the motherboard, far away from the video cards. Some manufacturers put the SATA ports on the same line as the PCI Express x16 slots and then the video card makes it difficult or even impossible for you to install cables on the SATA ports. The ATA-133 port and two of the SATA ports are placed facing the motherboard edge, so the cables on these connectors are installed parallel to the motherboard, preventing the problem described.
No floppy disk drive controller is present.
This motherboard has all the 12 USB 2.0 ports supported by the chipset, eight soldered on the rear panel and four available through two motherboard headers. Additionally ASUS M4A79XTD EVO comes with a FireWire (IEEE 1394) controller, providing two FireWire ports, one soldered on the rear panel (standard size) and one available through a header. Since the motherboard doesn’t come with an I/O bracket to for you to use the USB/FireWire headers, it is interesting to buy a case with one FireWire and four USB ports to go with this motherboard.
Audio is generated by the chipset using a VIA VT1708S codec, which is good but not professional-grade component, providing 7.1 audio with 24-bit resolution, 100 dB signal-to-noise ratio for the outputs, 95 dB signal-to-noise ratio for the analog inputs and 192 kHz sampling rate for both the outputs and inputs. If you want to work professionally converting and editing audio from an analog source (e.g., converting VHS tapes, LPs, etc to digital format) we highly recommend you to pick a motherboard with a codec with at least 100 dB signal-to-noise ratio (SNR) for its analog inputs (ADC).
This motherboard comes with an on-board optical SPDIF output, and coaxial SPDIF output is supported through an SPDIF out header present on the motherboard. If you want to use this output you will need to buy an I/O bracket containing it, as this motherboard doesn’t come with one.
On the analog side M4A79XTD EVO comes with fully independent 7.1 analog outputs, so you will be able to use all connectors at the same time.
A Gigabit Ethernet port is provided, controlled by a Realtek RTL8112L chip.
In Figure 7, you can see the motherboard rear panel with PS/2 mouse and keyboard connectors, eight USB 2.0 ports, optical SPDIF output, FireWire port, eSATA port, Gigabit Ethernet port and independent analog 7.1 audio outputs.
ASUS M4A79XTD EVO also has a serial port, available through a header on the motherboard. The board, however, doesn’t come with the connector required to use it.
[nextpage title=”Other Features”]
M4A79XTD EVO uses an eight-phase voltage regulator (plus two phases for the memory controller) using ferrite chokes, with the transistors using the passive heatsinks already shown on the first page. Read our Everything You Need to Know About the Motherboard Voltage Regulator Circuit to understand why this is a terrific configuration.
This motherboard has a unique feature, an over voltage/under voltage protection circuit, that prevents the motherboard and CPU from being fried if for some reason the power supply goes bad and starts feeding the motherboard with wrong voltages. This feature, however, comes disabled by default and you have to enable it through an option called “Anti Surgy Support” on the BIOS setup.
One small problem from this motherboard is that it uses an ATX12V connector without supporting EPS12V. As you can see in Figure 9, on the left side of this connector we have one of the chokes from the voltage regulator circuit and on the right side we have one of the pegs that holds the passive heatsink from the voltage regulator; this configuration prevents you from installing an EPS12V connector on this ATX12V connector. This way when buying this motherboard make sure to pick a power supply that has an ATX12V connector (almost all power supplies will have, but some very high-end models only feature an EPS12V connector).
Like other motherboards from ASUS, this one features Express Gate, an operating system stored inside the motherboard read-only memory that allows you to access the Internet without needing to load the operating system or even without having a hard disk drive installed.
In Figure 10, you can see all the accessories that come with ASUS M4A79XTD EVO.
[nextpage title=”Overclocking Options”]
ASUS M4A79XTD EVO offers a myriad of overclocking options. One interesting feature present on this motherboard is the availability of eight “memory slots” called “overclocking profiles” to store overclocking configurations. The options present (0604 BIOS) are:
- CPU base clock: can be adjusted from 200 MHz to 600 MHz in 1 MHz increments.
- PCI Express clock: can be adjusted from 100 MHz to 150 MHz in 1 MHz increments.
- CPU voltage: From 0.800 V to 1.700 V in 0.0125 V increments (the maximum depends on the CPU model, we used a Phenom II X4 965).
- CPU VDDA voltage: From 2.50 V to 2.80 V in 0.10 V increments.
- Memory controller (“CPU/NB”) voltage: From 0.800 V to 1.5500 V in 0.0125 V increments (the maximum depends on the CPU model, we used a Phenom II X4 965).
- HyperTransport (HT) voltage: From 1.20 V to 1.50 V in 0.02 V increments.
- Memory voltage: From 1.5 V to 2.5 V in 0.02 V increments.
- North bridge voltage: From 1.10 V to 1.40 V in 0.02 V increments.
- North bridge 1.8 V reference voltage: 1.80 V to 2.0 V in 0.1 V increments.
- South bridge voltage: From 1.20 V to 1.35 V in 0.15 V increments.
Memory timings can also be tweaked.
[nextpage title=”Main Specifications”]
ASUS M4A79XTD EVO motherboard main features are:
- Socket: AM3
- Chipset: AMD790X + SB750
- Super I/O: ITE IT8720F
- Clock generator: ICS 9LPRS477CKL
- Parallel ATA: One ATA-133 port controlled by the south bridge chip.
- Serial ATA: Seven SATA-300 ports, six controlled by the chipset (supporting RAID 0, 1, 5, 10 and JBOD) and one controlled by a Marvell 88SE6121 chip.
- External SATA: One eSATA-300 port controlled by the Marvell 88SE6121 chip.
- USB: 12 USB 2.0 ports, eight soldered on the motherboard and four available through two headers on the motherboard (the motherboard doesn’t come with I/O brackets for you to use these ports).
- FireWire (IEEE 1394): Two ports controlled by a VIA VT6315N chip, one standard-sized soldered on the rear panel and one available through a header (the motherboard doesn’t come with an I/O bracket for you to use this port).
- On-board audio: Produced by the chipset together with a VIA VT1808S codec (7.1 channels, 24-bit resolution, up to 192 kHz sampling rate for both the inputs and outputs, 90 dB signal-to-noise ratio for the inputs and 100 dB signal-to-noise ratio for the outputs). On-board optical SPDIF output.
- On-board LAN: One Gigabit Ethernet port controlled by a Realtek RTL8112L chip, which is connected to the system through one PCI Express x1 lane.
- Buzzer: No.
- Power supply required: ATX12V (not compatible with EPS12V).
- Slots: Two PCI Express 2.0 x16 slots (both working at x8 when two video cards are installed), two PCI Express x1 slots and two standard PCI slots.
- Memory: Four DDR3-DIMM sockets (up to 16 GB up to DDR3-1600/PC3-12800 or DDR3-1800 through overclocking).
- Number of CDs/DVDs provided: One.
- Programs included: Motherboard drivers and utilities.
- Extra features: Only solid capacitors, Express Gate, serial port, 2 oz. copper layers, over voltage/under voltage protections.
- More Information: https://www.asus.com
- Average price in the US*: USD 120.00
* Researched at Newegg.com on the day we published this First Look article.
Though not the most high-end motherboard available for the socket AM3 platform (this niche is filled by the AMD790FX chipset), ASUS M4A79XTD EVO presents a good range of fe
atures that will satisfy even the most demanding mainstream user, such as two PCI Express x16 slots (although they run at x8 when two video cards are installed), 7.1 audio with decent quality and on-board optical SPDIF output, one eSATA port, seven SATA-300 ports (six of them supporting RAID 0, 1, 5, 10 and JBOD) and ACC feature, that allows you to unlock hidden features from certain Phenom CPUs.
For USD 120 we consider this motherboard a real bargain if you are building a mid-range or even a high-end system based on a socket AM3 AMD CPU, especially when you put into the equation the construction quality, with only solid capacitors, 2 oz. copper layers, an 8+2 voltage regulator circuit and over voltage/under voltage protections.