The new ECS A890GXM-A2 is an updated version of the ECS A890GXM-A, which we already covered. Both are socket AM3 models based on the AMD 890GX chipset. Even though this chipset comes with integrated video, both motherboards come with three PCI Express x16 slots. The main differences between the two are the addition of two USB 3.0 ports and a better color scheme on the new model. Let’s check it out.

Before talking specifically about this motherboard from ECS, let’s briefly talk about the AMD 890GX chipset.

In the table below we provide a comparison between AMD 890GX and previous chipsets with integrated graphics from AMD: AMD 785G, AMD 790GX, and AMD 780G.

As you can see, the main specs of the graphics engine from the AMD 890GX are pretty similar to AMD 790GX’s, except that the AMD 890GX uses a DirectX 10.1 engine while AMD 790GX’s is DirectX 10.

The main difference on AMD 890GX is the use of a new south bridge chip, called SB850. This south bridge chip natively supports SATA-600 ports (a.k.a. “SATA 6 G”) and in fact this is the first chipset to arrived on the market with this feature (currently on motherboards based on other chipsets featuring SATA-600 ports an external controller chip must be used). Like the SB750 used with AMD 790GX, they support RAID level 5, a configuration not supported on the SB710 and SB700.

Notice how the SB850 supports only USB 2.0 ports. Motherboards based on this chipset that have USB 3.0 ports, like the A890GXM-A2 we will be exploring in this article, use an external controller chip.

Chipset AMD 890GX AMD 785G AMD 780G AMD 790GX
GPU Clock 700 MHz 500 MHz 500 MHz 700 MHz
Graphics Processors 40 40 40 40
ROPs 4 4 4 4
Engine HD 4290 HD 4200 HD 3200 HD 3300
DirectX 10.1 10.1 10 10
PCI Express 2.0 2.0 2.0 2.0
South Bridge Chip SB850 SB710 SB700 SB750
USB 2.0 Ports 14 12 12 12
SATA-300 Ports None 6 6 6
SATA-600 Ports 6 None None None
RAID 0, 1, 5, 10 0, 1, 10 0, 1, 10 0, 1, 5, 10
ATA-133 Ports 1 (2 devices) 1 (2 devices) 1 (2 devices) 1 (2 devices)

ROPs stand for “Raster Operation Units” and are also known as “Rendering Back-End Units.” They are the final stage on rendering a 3D image.

Other chipsets with on-board video from AMD include the AMD 690V, AMD 690G, AMD 740G, and AMD 780V. The AMD 690V, AMD 690G, and AMD 740G are based on a DirectX 9 graphics engine, while the AMD 780V is based on a DirectX 10 one. The AMD 780V is based on the Radeon HD 3100 engine, which runs at 400 MHz – clock is the main difference between the HD 3100, HD 3200 and HD 3300 engines.

Like the SB750, the SB850 south bridge chip supports an overclocking feature called “Advanced Clock Calibration” or simply ACC. How exactly this new feature works is completely obscure, as AMD does not explain how it works in details. All we know is that SB850 provides a feedback loop to some AMD CPUs, using some unused CPU pins, allowing you to unlock hidden features of the CPU – most commonly unlocking an extra CPU core, if you were lucky to get a CPU that has hidden disabled cores inside. You can read more about this feature here and here.

As you may know by now, on systems with integrated video the video memory is achieved by stealing part of the main RAM. Chipsets from AMD have a feature called SidePort, which is an optional memory chip soldered on the motherboard in order to increase video memory. This motherboard from ECS brings this feature, having 128 MB of GDDR3-1600 memory on-board to speed up video.

In Figure 1, you can see the basic block diagram of the AMD 890GX chipset.

ECS A890GXM-A2 motherboardFigure 1: AMD 890GX chipset


Gabriel Torres is a Brazilian best-selling ICT expert, with 24 books published. He started his online career in 1996, when he launched Clube do Hardware, which is one of the oldest and largest websites about technology in Brazil. He created Hardware Secrets in 1999 to expand his knowledge outside his home country.