[nextpage title=”Introduction”]

ECS A790GXM-A Black Series is a socket AM2+ motherboard based on the latest chipset from AMD, 790GX. Formerly known as RS780D, this chipset provides on-board video using a new graphics engine (Radeon HD 3300) with a dedicated 128 MB GDDR2 on-board memory (feature called “Side Port” by AMD) and also providing two PCI Express 2.0 x16 slots (running at x8 if both are used at the same time). In this review we will compare the performance of AMD 790GX to AMD 780G and GeForce 8200, and we will also analyze Hybrid CrossFire performance. Check it out.

The new AMD 790GX is basically an overclocked AMD 780G with a new south bridge chip, plus a dedicated 128 MB GDDR2 memory for use as video memory, instead of stealing memory from the system – if the video engine requires more than 128 MB, then it will “steal” the remaining amount from the main RAM. AMD 790GX engine is called Radeon HD 3300, while the engine used on AMD 780G is called Radeon HD 3200.

While AMD 780G is paired with SB700 chip, AMD 790GX is paired with the new SB750 chip, which brings basically two new features: RAID 5 support and a new 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 SB750 provides a feedback loop to Phenom processors using some unused CPU pins. This feature is only available on Phenom processors. You can read a little bit more about this feature here.

In the table below we provide a comparison between AMD 790GX and its predecessor, AMD 780G, and also with GeForce 8200.

Other current chipsets with on-board video from AMD include AMD 690V, AMD 690G, AMD 740G, AMD 780V and AMD 780G. AMD 690V, AMD 690G and AMD 740G are based on a DirectX 9 graphics engine, while AMD 780V, AMD 780G and the new AMD 790GX are based on a DirectX 10 one. AMD 780V is based on Radeon HD 3100 engine, which runs at 400 MHz – clock is the main difference between HD 3100, HD 3200 and HD 3300 engines. AMD 780V also doesn’t support Hybrid CrossFire configuration (more about this feature in just one second).

Chipset GeForce 8200 AMD 780G AMD 790GX
GPU Clock 500 MHz 500 MHz 700 MHz
Graphics Processors 16 40 40
Graphics Processors Clock 1,200 MHz 500 MHz 700 MHz
ROPs 4 4 4
DirectX 10 10 10
PCI Express 2.0 2.0 2.0
USB 2.0 Ports 12 12 12
SATA-300 Ports 6 6 6
RAID 0, 1, 0+1, 5 0, 1, 10 0, 1, 5, 10
ATA-133 Ports 1 (2 devices) 1 (2 devices) 1 (2 devices)
Hybrid SLI/CrossFire GeForce Boost Hybrid Graphics Hybrid Graphics

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.

Both chipsets support Hybrid SLI and Hybrid CrossFire technologies. These technologies allow the on-board video to work in parallel to a discrete video card under SLI or CrossFire modes, increasing gaming performance (usually when you install a “real” video card the on-board video is disabled). The video card must support this technology and in fact only a few support this. Read our tutorial SLI vs. CrossFire for further information.

In this review we will analyze the Hybrid CrossFire feature by installing a Radeon HD 3450 on the reviewed board, first with the on-board video disabled and then with it enabled and CrossFire mode activated.

In our benchmarking we will compare ECS A790GXM-A (AMD 790GX) to  Sapphire PI-AM2RS780G (AMD 780G) and ECS GF8200A Black Series (GeForce 8200).

Before going to our tests, let’s take an in-depth look ECS A790GXM-A.

[nextpage title=”The Motherboard”]

In Figure 1 you can have a good look at ECS A790GXM-A. Pay attention and you will see another model name printed on it: “ES780DM-A,” which is the name ECS was using before the official launch of AMD 790GX chipset. It is a socket AM2+ motherboard, meaning that it supports the new HyperTransport 3.0 and the “split plane” technologies used by AMD CPUs based on K10 architecture (i.e., Phenom CPUs). For more information read our Inside AMD K10 Architecture tutorial.

ECS A790GXM-A Black Series Figure 1: ECS A790GXM-A motherboard.

The first thing that caught our eye was the size of this motherboard. Usually motherboards with on-board video use the microATX form factor, but ECS A790GXM-A is an exception, using the regular ATX form factor. Motherboards based on AMD 790GX from other manufacturers should follow the same size. Also, motherboards with on-board video usually provide only one PCI Express x16 slot for you to install a “real” video card if you are not pleased with the performance provided by the integrated video processor – some motherboards don’t even have this option –, but ECS A790GXM-A provides not only one but two PCI Express 2.0 x16 slots (running at x8 if both are used at the same time). This allows you to add two discrete video cards under CrossFire mode. Other motherboards based on AMD 790GX will also follow this configuration.

The chipset supports Hybrid Graphics technology, which allows certain low-end video cards like Radeon HD 3450 to work in parallel with the on-board video in CrossFire mode, which provides a higher performance than a single add-on graphics card alone (read our SLI vs. CrossFire tutorial for a complete list of compatible cards).

ECS A790GXM-A Black Series Figure 2: Motherboard slots.

Besides the two PCI Express 2.0 x16 slots, this board also provides two x1 PCI Express slots and two regular PCI slots.

This motherboard requires a standard peripheral power connector installed on the motherboard (see Figure 2) for feeding the add-on video cards.

Another feature that differentiates this motherboard from low-end ones is the fact that its on-board video uses a dedicated 128 MB memory chip to be used as video memory. As you know the most common architecture used by motherboards with on-board video is called UMA, Unified Memory Architecture, where the chipset “steals” part of the RAM to be used as video memory. This motherboard will still use the UMA architecture if the video processor requires more than 128 MB of video memory. Using a dedicated chip instead of stealing part of the RAM also improves video performance, at least in theory – we will see if this holds true during our benchmarks.

This architecture is called “Side Port” by
AMD and on ECS A790GXM-A a Samsung K4N1G164QQ-HC25 1 Mbit GDDR2 chip is used (1 Mbit = 128 MB). The official maximum clock rate supported by this chip is 400 MHz (800 MHz DDR) and on this motherboard this chip is really accessed at 400 MHz (800 MHz DDR). On the motherboard setup you can decrease the speed used to access this memory, but not increase.

ECS A790GXM-A Black Series Figure 3: Dedicated memory chip for video memory.

This motherboard has two independent video outputs, one VGA and one HDMI (supporting audio), making it a good choice for a home theater PC (HTPC).

Another highlight from this motherboard is the presence of four memory sockets. Usually low-end motherboards have only two memory sockets, so having four of them on this board is a blessing, as it will help you adding more memory in the future without needing to replace your current memory modules.

It is always good to remember that with AMD processors the memory controller is embedded inside the CPU, so the amount and types of memory the system supports depend on the CPU, not on the motherboard. Socket AM2 and AM2+ processors support only DDR2 memories, with AM2 processors (i.e., Athlon X2) supporting up to DDR2-800 and with AM2+ processors (i.e., Phenom) supporting up to DDR2-1066.

All socket AM2/AM2+ CPUs support dual-channel feature so for the best performance you must install two or four memory modules (do not install just one memory module). For enabling dual-channel feature you must install the modules on sockets with the same color, if you are installing two modules.

[nextpage title=”The Motherboard (Cont’d)”]

As you could see on the first page, the chipset supports six SATA-300 ports and all are present on the reviewed board, supporting RAID levels 0, 1, 5 and 10 – RAID5 is a new feature for AMD/ATI chipsets.

This motherboard has an eight-channel on-board audio but provides analog jacks for only six channels, so full eight-channel support is only available through digital connection (SPDIF). This motherboard, on the other hand, provides one optical SPDIF (digital audio) output.

The audio codec used is Realtek ALC888, which features a 97 dB output signal-to-noise ratio (SNR) and a 90 dB input signal-to-noise ratio, with 24-bit resolution and up to 192 kHz sampling rate for its outputs and up to 96 kHz sampling rate for its inputs. While these specs are excellent to the mainstream user, people working professionally with analog audio capture and editing will be better off with a different motherboard or will have to buy an add-on sound card.

This motherboard also features two Gigabit Ethernet ports, each one controlled by an individual Realtek RTL8111C chip. Each controller is connected to the south bridge chip through individual PCI Express x1 lanes, which is perfect, as this configuration won’t limit the performance of your Gigabit Ethernet ports (controllers connected to the system using the regular PCI bus can face a bottleneck – i.e., may not be able to achieve the maximum Gigabit Ethernet performance).

In Figure 4, you can see the rear panel of the motherboard. There you will find one mouse PS/2 connector, one keyboard PS/2 connector, VGA output, serial port, six USB 2.0 ports, HDMI output, two Gigabit Ethernet ports, 5.1 channel analog audio outputs and optical SPDIF output. As you can see there is no parallel port on the rear of the motherboard.

ECS A790GXM-A Black Series Figure 4: Rear connectors.

This motherboard also provides other smaller yet important features. Like other members from ECS’ “Black Series” the voltage regulator circuit uses ferrite chokes (which present a lower power loss compared to the iron chokes traditionally used on this circuit) and solid aluminum capacitors (which prevent the infamous capacitor leakage problem), plus it has passive heatsinks on top of the MOSFET transistors. Also most of the capacitors used on the rest of the motherboard are also solid, which is great. The caps that aren’t solid are from OST, a Taiwanese company.

ECS A790GXM-A Black Series Figure 5: Voltage regulator circuit featuring ferrite chokes, solid capacitors and passive heatsink.

Another nice feature is the presence of the power and reset switches soldered directly on the motherboard, see Figure 6.

ECS A790GXM-A Black Series Figure 6: Power and reset switches.

Before going to our benchmarking, let’s recap the main features from this motherboard.

[nextpage title=”Main Specifications”]

ECS A790GXM-A main features are:

  • Socket: AM2+.
  • Chipset: AMD 790GX (codenamed RS780D) + SB750 south bridge.
  • Clock generator: ICS 9LPRS471
  • Super I/O: ITE IT8726F
  • Parallel IDE: One ATA-133 port controlled by the chipset.
  • Serial IDE: Six SATA-300 ports controlled by the chipset (RAID 0, 1, 5 and 10).
  • USB: 12 USB 2.0 ports (six soldered on the motherboard rear panel and six available through I/O brackets; this board doesn’t comes with I/O brackets for using these extra ports).
  • FireWire (IEEE 1394a): No.
  • On-board audio: Produced by the chipset together with a Realtek ALC888S codec (eight channels, 24-bit resolution, up to 96 kHz sampling rate for the inputs and up to 192 kHz sampling rate for the outputs, 90 dB signal-to-noise ratio for the inputs and 97 dB signal-to-noise ratio for the outputs).
  • On-board video: Yes, Radeon HD 3300 engine with two independent outputs, one VGA and one HDMI and with dedicated on-board 128 MB memory (one Samsung K4N1G164QQ-HC25 chip), feature called “Side Port” by AMD.
  • On-board LAN: Two Gigabit Ethernet ports controlled two Realtek RTL8111C chips, connected to the system through a PCI Express x1 lane.
  • Buzzer: No.
  • Power supply required: ATX12V 2.x (24-pin).
  • Slots: Two x16 PCI Express 2.0 slots (running at x8 if both are used at the same time), two PCI Express x1 slots and two PCI slots.
  • Memory: Four DDR-DIMM sockets (up to 8 GB up to DDR2-800/PC2-6400 or DDR2-1066/PC2-8500, depending on the CPU).
  • Number of CDs that come with this motherboard: One.
  • Programs included: Motherboard drivers and utilities.
  • More Information: https://www.e
  • Average price in the US: We reviewed this product before it arrived on the market. According to ECS it will come with a suggested price of USD 115.00.

[nextpage title=”How We Tested”]

During our benchmarking sessions, we used the configuration listed below. Between our benchmarking sessions the only variable was the motherboard being tested and the addition or removal of a “real” video card (Sapphire Radeon HD 3450).

Hardware Configuration

Software Configuration

  • Windows Vista Ultimate 32-bit
  • Service Pack 1

Driver Versions

  • NVIDIA nForce driver version (includes video driver): 18.11
  • ATI motherboard/video driver version: Catalyst 8.6

Software Used

Some Information About our Methodology

All motherboards included in our comparison were configured with 256 MB shared memory, so ECS A790GXM-A had 384 MB available (128 MB on-board and 256 MB shared).

Since we were reviewing a motherboard with on-board video, we were very interested in comparing its 3D video performance with the performance achieved by other motherboards with on-board video and also with a very low-end video card, so we could have an idea of how slower on-board video is compared to a very inexpensive video card. We chose Sapphire Radeon HD 3450 with 256 MB and 64-bit memory interface because this is one of the cheapest video cards available today.

We chose an entry-level CPU to go with the motherboard, an Athlon X2 4600+, because that is the same CPU we used on other recent reviews from motherboards with on-board video targeted to AMD systems, and using the same CPU would speed up the publishing of the present review, as we wouldn’t need to re-test the other motherboards. It is our opinion that a regular user wouldn’t pick a high-end CPU to go with a motherboard with on-board video and that is why we kept this CPU, but of course there is space for discussion, as AMD is clearly targeting AMD 790GX to Phenom CPUs, otherwise they wouldn’t include ACC feature. Unfortunately there is no way to create a methodology that pleases all opinions and that is why we are sticking to ours. On other websites you can find reviews for AMD 790GX-based motherboards using other methodologies, which is great, as you can have an idea of their performance using different components and programs. It would make no sense if all websites published the same tests and results, don’t you think?

By the way, the CPU we used doesn’t suffer from the problem some AMD CPUs have of not being able to access memories at their full speed.

Even though we had DDR2-1066 memories, we configured them as DDR2-800 units, for two reasons. First, entry-level PCs won’t use DDR2-1066 memories and, second, Athlon X2 can only access memories up to 800 MHz.

Error Margin

We adopted a 3% error margin; thus, differences below 3% cannot be considered relevant. In other words, products with a performance difference below 3% should be considered as having similar performance.

[nextpage title=”Overall Performance: PCMark Vantage”]

The new PCMark Vantage program simulates the use of real-world applications and gives scores for the following categories:

  • PCMark
  • Memories
  • TV and Movies
  • Gaming
  • Music
  • Communications
  • Productivity
  • HDD

For a detailed description of each one of these tests, please download and read the PCMark Vantage Reviewer’s Guide.

You can see the results for each category below. We are not going to compare the results for the Memories and HDD suites.

This benchmarking was done using the motherboard on-board video. Usually the motherboard with the fastest graphics engine achieves the highest score on this program. See the results below.

ECS A790GXM-A Black Series

Here we got some very interesting results. AMD 790GX and AMD 780G achieved the same performance on Music and Communications benchmarks, with Sapphire PI-AM2RS780G (AMD 780G) being a little bit faster than ECS A790GXM-A Black Series (AMD 790GX) on the final PCMark score (5%) and on the TV and Movies benchmark (8%). However, on Gaming and Productivity benchmarks ECS A790GXM-A Black Series was 7% and 23% faster, respectively. This huge difference on Productivity is probably showing that AMD 790GX has a higher 2D video performance than AMD 780G.

Compared to ECS GF8200A Black Series (NVIDIA GeForce 8200), the reviewed board was 28% faster in Gaming, showing that AMD 790GX has a better 3D engine than GeForce 8200, 18% faster in Productivity, 6% faster in Music and a 7% higher overall score. Both motherboards achieved the same performance under TV and Movies and Communications.

[nextpage title=”3DMark06 Professional”]

3DMark06 measures Shader 3.0 (i.e., DirectX 9.0c) performance. We ran t
his software under its default configuration. For this test we also included the result achieved by a 64-bit Sapphire HD 3450 card installed in the motherboard PCI Express x16 slot while disabling the motherboard’s on-board video, so we can have an idea of the performance of a very low-end video card compared to the on-board video of the reviewed motherboard. We also enabled Hybrid Graphics, i.e., configured our Radeon HD 3450 to work in parallel with the on-board video in CrossFire mode, to see if there was any performance gain. The results you can see below.

ECS A790GXM-A Black Series

On 3DMark06 the reviewed motherboard from ECS achieved a performance 26.55% higher than Sapphire PI-AM2RS780G (AMD 780G) and 143.77% higher than ECS GF8200A Black Series (NVIDIA GeForce 8200).

A very low-end Radeon HD 3450 video card was “only” 14.32% faster than the on-board video provided by AMD 790GX. Usually even very low-end video cards are far faster than on-board video solutions and it is a surprise to see an on-board video almost at the same level of an entry-level add-on card.

Enabling Hybrid CrossFire technology – which makes Radeon HD 3450 to work in parallel with the on-board video to increase performance – performance increased 54% compared to the Radeon HD 3450 alone with the on-board video disabled. This is impressive, because this 50%+ performance boost is gained absolutely for free.

[nextpage title=”3DMark Vantage”]

3DMark Vantage measures Shader 4.0 (i.e., DirectX 10) performance. We couldn’t run this program with GeForce 8200 nor with AMD 780G even running the lowest video configuration possible, called “Entry Level.” Surprisingly enough we were able to run this program with AMD 790GX, which is impressive – this is the first time we’ve seen an on-board video solution being able to run this program. Below you can see the results for this chipset and for the add-on 64-bit Radeon HD 3450 installed on a PCI Express x16 slot from the reviewed motherboard with its on-board video disabled. When we enabled them to work together in parallel under CrossFire, however, the system rebooted. We tried several times to no avail.

We are presenting two results: the Entry score – which puts CPU performance for physics calculations into the equation – and the GPU score – which is the score of only the GPU.

ECS A790GXM-A Black Series

ECS A790GXM-A Black Series

As you can see the integrated graphics from AMD 790GX and Radeon HD 3450 achieved the same performance level on 3DMark Vantage, which is really impressive. AMD 790GX is not only the first integrated graphics chipset we’ve seen running 3DMark Vantage, but it also achieved the same performance as an entry-level add-on card.

[nextpage title=”Half-Life 2: Episode Two”]

Half-Life 2 is a popular franchise and we benchmark the video cards using Episode Two with the aid of HOC Half-Life 2 Episode Two benchmarking utility using the “HOC Demo 1” provided by this program. We ran the game under 1024×768 with no anti-aliasing and bilinear filtering, i.e., using the lowest image quality possible. The results, given in frames per second, you see below.

ECS A790GXM-A Black Series


On this game the on-board video from ECS A790GXM-A Black Series (AMD 790GX) achieved the same performance as a 64-bit Radeon HD 3450, which is remarkable. The on-board video from the reviewed motherboard was 30.30% faster than the one from Sapphire PI-AM2RS780G (AMD 780G) and 126.32% faster than the one from ECS GF8200A Black Series (NVIDIA GeForce 8200).

Enabling Hybrid CrossFire technology performance increased 50% compared to the Radeon HD 3450 alone with the on-board video disabled. This is impressive, especially because you gain this performance boost for free if you have a compatible video card.

[nextpage title=”Unreal Tournament 3″]

Unreal Tournament 3 is the latest installment from this famous first person shooter franchise, supporting DirectX 10 graphics when installed on Windows Vista with a DX10 compatible card (which was our case). We upgraded Unreal Tournament 3 to version 1.2 and benchmarked it with the help of HOC UT3 benchmarking utility using the “Containment” demo, disabling anisotropic filtering and running the game at 1024×768. The results are below, in frames per second (FPS).

ECS A790GXM-A Black Series

On this game the on-board video from ECS A790GXM-A Black Series (AMD 790GX) achieved again the same performance as a 64-bit Radeon HD 3450, which is remarkable. The on-board video from the reviewed motherboard was 22.22% faster than the one from Sapphire PI-AM2RS780G (AMD 780G) and 69.23% faster than the one from ECS GF8200A Black Series (NVIDIA GeForce 8200).

Enabling Hybrid CrossFire technology performance increased 47.83% compared to the Radeon HD 3450 alone with the on-board video disabled. This is impressive, especially because you gain this performance boost for free if you have a compatible video card.

[nextpage title=”Quake 4″]

We upgraded Quake 4 to version 1.4.2 and ran its multiplayer demo id_perftest with SMP option enabled (which allows Quake 4 to recognize and use more than one CPU), under 1024×768 with image quality settings configured at “low.” You can check the results below, given in frames per second.

ECS A790GXM-A Black Series


On Quake 4 AMD 790GX was 28.75% faster than AMD780G and 284.96% faster than GeForce 8200. Our low-end Radeon HD 3450 was 69.53% faster than the on-board video produced by AMD 790GX.

Enabling Hybrid CrossFire technology performance increased only 5.32% compared to the Radeon HD 3450 alone with the on-board video disabled.

[nextpage title=”Overclocking”]

ECS A790GXM-A Black Series provides some overclocking options, including:

  • GPU internal clock: From 150 MHz to 2000 MHz in 1 MHz increments (under “Advanced Chipset Setup”).
  • Base clock: From 200 MHz to 355 MHz in 5 MHz increments.
  • CPU voltage: +20 mV (+0.020 V) to +300 mV (+0.300 V) in +20 mV (+0.020 V) increments.
  • Memory voltage: +10 mV (+0.010 V) to +150 mV (+ 0.150 V) in +10 mV (+0.010 V) increments.
  • North bridge (NB) voltage: +5 mV (+0.005 V) to +75 mV (+0.075 V) in +5 mV (+0.005 V) increments.
  • South bridge (SB) voltage: 1.20 V to 1.35 V in 0.05 V increments.
  • Side port voltage: 1.8 V to 2.1 V in
    0.1 V increments.
  • Full memory timings configuration.

ECS A790GXM-A Black Series Figure 7: Overclocking options.

ECS A790GXM-A Black Series Figure 8: Memory timings adjustments.

With this motherboard we could increase the base clock from our Athlon X2 4600+ from 200 MHz to 230 MHz with the CPU running stable, even though at this configuration we could see some artifacts on the video when in 2D mode (3D mode ran just fine). Under this overclocking our CPU was running internally at 2,760 MHz, a 15% increase from its default clock rate of 2.400 MHz. This is the same overclocking level we achieved with ECS GF8200A Black Series.

[nextpage title=”Conclusions”]

You should not see ECS A790GXM-A as a low-end motherboard with on-board video for AMD-based systems, because it isn’t – and that is why it will reach the market costing more than motherboards with on-board video based on other chipsets.

This is a mid-range motherboard full of desirable features not present on traditional motherboard with integrated graphics: bigger size (meaning more slots), presence of two PCI Express 2.0 x16 slots (allowing you to install up to two add-on video cards under CrossFire configuration), dedicated video memory (providing a higher performance for its integrated video), four memory sockets, optical SPDIF output, HDMI output (with audio support), two Gigabit Ethernet ports, RAID 5 support and a decent audio codec for the Average Joe.

You should see this motherboard as a mid-range board that happens to have a decent on-board video, which can be used while you are still deciding which video card you want to buy, in an emergency if your video card is defective or if you want to boost the performance of your Hybrid CrossFire-compatible video card.

Even though in some games AMD 790GX achieved the same performance level of a 64-bit Radeon HD 3450, it is still really tough to play decently with an on-board video solution, as you will still get low frame rates even with all image quality enhancements disabled and running at a low resolution for today’s standards (1024×768).

This motherboard, in our opinion, is too expensive if the only feature you are interested is the fastest on-board video and you won’t use the extra features brought by it. It brings a 3D performance increase between 20% and 30% over AMD 780G but it doesn’t cost only 30% more than an AMD 780G-based motherboard!

The presence of an HDMI connector is a blessing for some people and a curse to other. If you are building a home theater PC (HTPC) the HDMI connector with audio support and the optical SPDIF out are a must and this motherboard will probably fulfill your needs. However, if you don’t plan to connect your PC to an HDTV set you will miss a DVI connector – which isn’t present on this motherboard – since most LCD monitors come with DVI connection, which provides better quality over VGA.

Another feature we must talk about is overclocking, especially because AMD is pushing AMD 790GX as an overclocking-friendly platform. Even though ECS A790GXM-A allows you to massively overclock the chipset graphics engine, provides several voltage adjustments and features full memory timings configuration, it lacks better clock adjustments: the CPU base clock can be adjusted only in 5 MHz increments (and not at 1 MHz increments as usual) and you can’t adjust the PCI Express or the HyperTransport clocks, which is imperative for a better overclocking.

In summary, ECS A790GXM-A can be a good pick if you are building a mid-range PC and plan to decide which video card you will pick later or will buy a video card compatible with Hybrid CrossFire. The presence of the on-board video – even though it is the fastest around – shouldn’t be the only weight in your decision.