AMD 890GX in Action: ASUS M4A89GTD PRO/USB3 and Gigabyte 890GPA-UD3H Mainboards

The new AMD 890GX chipset offers a faster Radeon HD 4290 core and incorporates an SB850 South Bridge that supports Serial ATA 6 Gbps. We will study the new chipset's features using two mainstream mainboards from ASUS and Gigabyte.

by Ilya Gavrichenkov
04/01/2010 | 02:22 PM

The evolutionary changes in the PC market have transformed the structure of a computer platform. The chipset, which used to support peripheral interfaces as well as to link the CPU, memory and graphics subsystem, has lost its importance, its key components, like the memory controller, having moved into the CPU. As the result, the chipset now often degenerates into a single chip that combines a few controllers of external interfaces. This explains why any changes in the chipset market have been so few and so infrequent lately. In fact, new chipsets come out only when a new CPU series or a new CPU socket arrives. 

 

Chipsets for AMD processors have not yet fully become an auxiliary component, though. AMD was the first CPU maker to move the memory controller into the CPU, but chipsets for AMD processors can still contain an integrated graphics core. It is the improvement of this core that has been the main reason for new Socket AM3 chipsets to keep on coming out. Half a year ago, this gave birth to the AMD 785G and now, under similar circumstances, we meet the new AMD 890GX. 

Although free from any momentous innovations, the AMD 890GX has been warmly welcomed by mainboard makers because this may be the reason for some users to upgrade their computers. When there are no new chipsets, mainboard sales decline considerably, especially in the sector of top-end, enthusiast-targeted models. The AMD 890GX, on its part, is going to appeal especially to users who want to utilize its integrated graphics core. As a matter of fact, the 890GX has been AMD's answer to Intel's Clarkdale processors with their rather fast HD Graphics core. Besides, the new chipset's South Bridge has been improved, so purchasing an 890GX-based mainboard makes sense even if an external graphics card is going to be used.  

We will discuss the new features of the AMD 890GX in this review and take a look at a couple of mainboards based on it. The mainboards are from the major makers ASUS and Gigabyte.

ATI Radeon HD 4290 Graphics Core 

Radeon HD 4280

Contrary to our expectations, there is nothing particularly new about the graphics core integrated into the AMD 890GX chipset. It is largely similar to the core found in the older AMD 785G. That's why the names of the cores differ so little, by the way: Radeon HD 4290 and Radeon HD 4200. There is still no DirectX 11 support as the new core only complies with the DirectX 10.1 specifications. The only thing the developer did was to increase the performance slightly so that the Radeon HD 4290 could be competitive to computers that use the integrated graphics core of Intel's LGA1156 processors. 

What is the simplest way to boost performance? Increase the GPU's clock rate, of course! Therefore, the Radeon HD 4290 core in the AMD 890GX is clocked at 700 MHz whereas the Radeon HD 4200 used to be clocked at 500 MHz. Otherwise, the two cores are identical, both being based on the RV620 architecture with 40 shader processors. 

The video engine, UDV2, has remained the same as in the AMD 785G. It did not actually call for improvement since its functionality is up to today's requirements. As we saw in our tests of the AMD 785G, the CPU load was very low when playing video using that graphics core. The UVD2 engine offers hardware decoding support for MPEG2, VC-1 and H.264 and can process two independent streams simultaneously. On the downside is the inability of the AMD 890GX (and 785G) to transmit TrueHD, DTS-HD or uncompressed multichannel LPCM audio via HDMI, making it less appealing for HTPC systems. 

Like the Radeon HD 4200, the graphics core in the AMD 890GX chipset can use not only some of the computer's main system memory for its purposes, but also a dedicated 128-megabyte DDR3-1333 video buffer (Sideport Memory) represented by a separate memory chip. Besides using this buffer as dedicated graphics memory, the Radeon HD 4290 can also utilize it as cache to improve performance while working with system memory. It must be noted that mainboard makers did not often implement Sideport Memory technology in their AMD 785G-based products whereas most of AMD 890GX-based ones are going to be equipped with that video buffer. 

We performed a series of tests to check out the 3D performance of the new chipset and compared the AMD 890GX, AMD 785G and Intel HD Graphics. For this comparison we took Intel Core i3-540 and AMD Athlon II X4 635 processors and the following mainboards: Gigabyte GA-H55M-UD2H, Gigabyte GA-MA785GT-UD3H and Gigabyte GA-890GPA-UD3H.

Radeon HD 4290 Performance
Click to enlarge

The tests suggest that AMD's solution works. The higher clock rate proves to be sufficient to make the AMD 890GX the fastest chipset with integrated graphics core. The Sideport Memory adds the graphics core a dedicated memory bus and helps increase 3D performance, making the Radeon HD 4290 an unchallenged leader.

New South Bridge 

The AMD 890GX sports the new South Bridge SB850. Frankly speaking, we don't think the SB750 chip that was used in AMD's previous chipsets is outdated, but the developer has just added a couple of hot features. First, it is a new Serial ATA controller that supports data-transfer speeds up to 6 Gbps. The AMD 890GX is in fact the world's first South Bridge to support the new interface. It must be noted, however, that the higher speed of SATA 6 Gbps is only a marketing advantage so far. It will only bring about tangible performance benefits when there appear appropriate SSDs capable of reading data at a speed higher than 300 MBps, which is the peak bandwidth of the current SATA-300 standard. 

The support for the newest version of the SATA standard is not the only special feature about the SATA controller implemented in the SB850. AMD's engineers have given up using technologies they had previously licensed from Promise, so the new Serial ATA controller is AMD's own design.  

Considering the SATA-600 implementation, it is rather odd that the AMD SB850 has no SuperSpeed USB 3.0. Instead, this South Bridge only offers 14 USB 2.0 ports. AMD suggests that USB 3.0 is implemented by means of external USB 3.0 controllers connected to the South Bridge via two PCI Express 2.0 lanes. This implementation ensures the full bandwidth of the new USB standard with data-transfer speeds up to 500 MBps.

Overall, the AMD SB850 looks a more advanced solution than its predecessor, yet some of highly anticipated features are still missing. 

The SB850 does not have the exclusive Advanced Clock Calibration technology found in AMD's earlier South Bridges. It helped increase overclockability and power efficiency of first-generation Phenom processors and was later found suitable for unlocking disabled cores in dual- and triple-core Athlon II and Phenom II processors. At one time, AMD tried to block ACC for its new CPUs in the BIOS but a number of mainboards still support this technology. No wonder that it is now missing in the chipset. On the other hand, this does not mean that 890GX-based mainboards won't be able to unlock disabled CPU cores. For example, ASUS has successfully implemented this feature in its 890GX-based board, suggesting that users can still enjoy undocumented capabilities of AMD's dual- and triple-core CPUs. 

CrossFireX Technology 

AMD's new chipset consists of two chips: a North Bridge (incorporating the integrated graphics core and a controller of the graphics bus PCI Express x16 2.0) and a South Bridge. 

AMD obviously did not intend the 890GX only as an integrated solution. As opposed to the 785G, the new chipset supports CrossFireX. Its PCI Express 2.0 x16 bus can be split up into two x8 buses, allowing to build top-performance graphics subsystems consisting of two graphics cards. 

That's why the AMD 890GX should not be viewed as an ordinary integrated chipset for inexpensive and compact mainboards. It is instead positioned as a solution for mainstream systems, and most mainboard makers are going to install it onto their full-size and functionally rich products. 

AMD is also planning to introduce a discrete chipset of the new generation called AMD 890FX. It will be accompanied with the same SB850 South Bridge and targeted at expensive computers. As opposed to the 890GX, it supports the most advanced CrossFireX implementation with two PCI Express 2.0 buses, each in x16 mode.  

The AMD 890GX also boasts AMD's Dual Graphics technology. Its point is that the resources of the integrated Radeon HD 4290 core can be combined with the external graphics card to deliver higher overall performance. This technology works with the Radeon HD 5450 card, ensuring a 25% performance boost in 3D games.

Dual Graphics can be only interesting for users of entry-level graphics cards like the Radeon HD 5450, though. The more expensive Radeons have enough GPU resources of their own and won't have any performance benefits from the integrated graphics core due to the high overhead resulting from the interaction of the external and integrated GPUs. 

Mainboards

ASUS M4A89GTD PRO/USB3  

The 890GX-based mainboard from ASUS looks unusual as its developers have made a few original design decisions. It does not mean we have any complaints about the positioning of the components on the PCB. The ASUS M4A89GTD PRO/USB3 is a handy device and can hardly present any installation related problems. 

The special feature of this mainboard is the way the two PCIe x16 slots for graphics cards are installed on it. The primary slot is farther from the CPU and can work in x16 mode. The second, gray-colored, slot works in x8 mode and can only be utilized for CrossFireX configurations. It means that if you have only one graphics card in your computer, you will have to install it closer to the mainboard's bottom edge, often blocking one of the two PCI slots. 

Yet another peculiarity of the ASUS M4A89GTD PRO/USB3 is that it cannot automatically change the operation mode of the PCIe x16 slots. If there is only one graphics card in the system, a dummy card must be inserted into the gray PCIe x16 slot to switch the blue one from x8 into x16 mode. Perhaps not very handy for the end-user, this mechanism helped the manufacturer get rid of an electronic switch and make the mainboard a little bit cheaper.

This cost saving was useful as the manufacturer got the opportunity to install a number of onboard controllers on the M4A89GTD PRO/USB3 without increasing the price of the product much. First of all, there is a NEC controller supporting two USB 3.0 ports (the AMD SB850 South Bridge does not support this interface natively). ASUS's mainboard has a total of 14 USB ports. Two USB 3.0 and four USB 2.0 ports can be found on its back panel, and eight more are designed as onboard headers.

 

Additional controllers are also responsible for the mainboard's IEEE1394 interface, Gigabit Ethernet (ASUS preferred a PCIe x1 Realtek 8111E controller to the MAC controller integrated into the chipset), and eSATA. Thus, besides the six mentioned USB ports, the mainboard's back panel offers one IEEE1394 port, a network port (RJ-45), one eSATA connector, and a PS/2 port for keyboard. There are also six analog audio sockets and one optical SPDIF connector implemented through an eight-channel controller ALC892. The mainboard also offers as many as three interfaces to connect a monitor to the integrated graphics core: D-Sub, DVI and HDMI. 

The CPU power circuit consists of an eight-channel voltage regulator (officially supporting CPUs with a TDP of 140 watts), with two more phases dedicated to the CPU-integrated North Bridge (which comprises a memory controller and L3 cache). It is cooled by a massive aluminum heatsink connected to the heatsink on the chipset's North Bridge.

The heatsink on the AMD 890GX chip is secured firmly with screws whereas the heatsink on the voltage regulator is fastened with two spring-loaded plastic locks and the thermal interface doesn't look trustworthy, resembling a piece of insulation tape. ASUS's engineers must have relied on the sheer size of the heatsink, but the large size made it necessary to install a rather funny and tall 8-pin ATX power connector. 

The mainboard is free from enthusiast-targeted features like diagnostic LEDs or Power On, Reset and Clear CMOS buttons. Instead, there is a MemOK button and two switches: Turbo Key II and Core Unlocker. The button can be pressed to start the mainboard up with failsafe memory settings, preventing the system from hanging up. The Turbo Key II feature is for automatic CPU overclocking. And Core Unlocker is ASUS's very exclusive switch that unlocks disabled cores in dual- and triple-core processors. That's in fact the replacement to ACC technology. 

The mainboard's BIOS suggests that the ASUS M4A89GTD PRO/USB3 can be viewed as a platform for overclocking experiments. The key performance-related settings, traditionally for ASUS products, can all be found in a separate BIOS page called Ai Tweaker.

So, the mainboard offers everything necessary to control the frequencies of the CPU, memory, CPU-integrated North Bridge, and HyperTransport bus. You can also adjust a variety of voltages including not only those of the CPU, memory and CPU-integrated North Bridge, but also of the chipset, SidePort Memory and HyperTransport bus. Both the list of voltages and the adjustment ranges are extensive.

It is important that the CPU voltage can be set not only as an absolute value but relative to the default level as this helps keep all power-saving technologies running when the CPU gets overclocked. Besides, the BIOS has a set of Load-Line Calibration technologies that prevent a voltage drop on the CPU when the power regulator is under heavy load. 

There are special options that allow overclocking the integrated Radeon HD 4290 graphics core and Sideport Memory. 

The memory subsystem settings are exhaustive and informative. Like with the voltage settings, you can see the current value of a parameter next to the one you select.

The CPU Configuration section is where you can access CPU technologies. The function of the Core Unlocker switch is duplicated here. By the way, if you are trying to transform a dual-core CPU into a triple-core one, the BIOS gives you the choice of which of the disabled cores should be turned on, which increases the possibility of success.

The Hardware Monitor section is good, too. Besides offering a number of parameters available for monitoring, ASUS has improved its Q-Fan technology that controls the speed of the system fans depending on temperature. Now the user can specify the correlation between speed and temperature by himself. Moreover, this technology works not only for PWM-controlled fans but also for ordinary 3-pin models. 

You can overclock your computer based on an ASUS M4A89GTD PRO/USB3 mainboard not only through the BIOS but also through a special tool called TurboV ECO included into the kit. It allows changing voltages and frequencies without leaving the OS.

 

By the way, this tool can also be used to overclock the graphics core but a special graphics driver must be installed for the appropriate options to become accessible. Besides changing the parameters manually, you can try the automatic overclocking features available in TurboV EVO. This utility can remember multiple overclocking profiles, allowing to switch between them by pressing hot buttons.

Gigabyte 890GPA-UD3H 

Gigabyte's 890GX-based mainboard, the 890GPA-UD3H model, is a typical product that has all the traits of this brand's earlier Socket AM3 mainboards. As opposed to the above-discussed ASUS M4A89GTD PRO/USB3, there is nothing unusual about the design of the Gigabyte 890GPA-UD3H. It is quite a pleasure to use and offers a traditional selection of interfaces. 

Like its ASUS competitor, the Gigabyte 890GPA-UD3H has a couple of graphics slots for using two graphics cards in PCIe 2.0 x8 + x8 mode. The switching of the slots is automatic. There is no need to insert a dummy card into any of the slots if only one graphics card is used. The primary PCIe x16 slot is the one which is closer to the CPU socket. If you install a graphics card with a tall cooler, one of the mainboard's three PCIe x1 slots is going to be blocked. The two PCI slots available on board will be accessible then. 

After our inspection of the ASUS mainboard above, we cannot get rid of the feeling that the Gigabyte 890GPA-UD3H is like a twin brother of it. The two mainboards are very similar. Particularly, Gigabyte's engineers installed about the same selection of onboard controllers. The Gigabyte 890GPA-UD3H has 14 USB ports like the ASUS mainboard. 12 of those ports are connected to the SB850 South Bridge and two USB 3.0 ports are implemented with the NEC controller we have already seen above. 

Like the ASUS mainboard, the Gigabyte 890GPA-UD3H comes with a FireWire controller, a Gigabit Ethernet controller (which is a Realtek 8111D here), an eight-channel ALC892 codec, and an additional SATA controller. As opposed to the ASUS, the Gigabyte mainboard does not support eSATA. Instead, it offers six SATA-600 ports via the chipset and two SATA-300 ports via the additional controller. 

Unlike their colleagues from ASUS, Gigabyte's engineers have provided support for legacy interfaces. The 890GPA-UD3H offers one PATA slot, one COM port, and even a connector for a 3.5-inch floppy drive which is not available on the ASUS M4A89GTD PRO/USB3. 

The mainboard's back panel carries three ports to connect monitors to the integrated graphics core: D-Sub, DVI and HDMI. It must be noted that, like on any other mainboard based on AMD's integrated graphics chipsets, the DVI and HDMI ports cannot be used simultaneously and you cannot connect analog monitors to the DVI port even via an adapter.

 

The rest of the interfaces you can find at the mainboard's back are standard enough. There are four USB 2.0 ports, two USB 3.0 ports, one IEEE1394 port, a PS/2 connector for mouse or keyboard, a Gigabit Ethernet port, six analog audio sockets and an optical SPDIF. Additionally, there are eight more USB 2.0 ports and two IEEE1394 ports available as onboard headers. The only special feature is that the reinforced USB power circuit can give more power to USB devices than usual. 

There is nothing extraordinary about the CPU power circuit. It consists of only four channels plus an additional channel for the CPU-integrated North Bridge but can easily cope with 140W CPUs. The power converter's transistors are cooled by a medium-sized heatsink connected to the North Bridge heatsink with a heat pipe.

Both heatsinks are secured with spring-loaded plastic locks and use a rubber-like thermal interface of rather mediocre quality. By the way, Gigabyte's engineers have tucked the Sideport Memory chip down under the chipset heatsink, but the latter does not actually touch the chip and does not cool it. 

Although the Gigabyte 890GPA-UD3H is targeted at high-performance configurations, it lacks many enthusiasts-oriented technologies. It does not have a POST controller or diagnostic LEDs or any buttons and switches. The manufacturer only did not save on the two BIOS chips.

However, the ordinary appearance of the Gigabyte 890GPA-UD3H conceals advanced software tools that can be used to overclock the CPU and fine-tine system performance. Most of them can be found on the MB Intelligent Tweaker page of the BIOS Setup. 

Like any Socket AM3 platform for enthusiasts, the Gigabyte 890GPA-UD3H offers all the options for controlling the clock generator's frequency and the accompanying multipliers (of the frequencies of the CPU, CPU-integrated North Bridge, HyperTransport bus and system memory). It is handy that when you change any of these values, the mainboard shows you what resulting frequencies of the different system components you are going to have. 

Voltage tweaking is just as good here. You can change the voltage on the CPU and its North Bridge, on the memory chips, on the AMD 890GX chip and on the Sideport Memory. The CPU voltages are set as relative rather than absolute values, so all the power-saving technologies keep on working even when the system is overclocked. By the way, the settings are all accompanied by information fields that show the current values of the voltages to make it simpler to see the big picture for the whole computer. 

Despite the lack of any BIOS option to counteract a voltage drop under load, this effect does not show up on the Gigabyte 890GPA-UD3H because the power circuit of this mainboard is governed by a new linear feedback scheme that adjusts the voltages automatically. Thanks to it, the voltages do not fluctuate much under different loads. 

Memory latency parameters can be found on a separate page. You get a full selection of adjustable timings here while the information about recommended values shown nearby makes it easier to manually configure the memory subsystem. 

There is a special BIOS page for overclocking the integrated graphics core. You can change the clock rate of the Radeon HD 4290 as well as of the Sideport memory. 

CPU technologies can be accessed through the Advanced BIOS Features page. Unfortunately, you can only enable Cool'n'Quiet and virtualization technologies here. The Gigabyte 890GPA-UD3H cannot unlock disabled CPU cores like the ASUS mainboard. 

The hardware monitoring section of the Gigabyte mainboard is inferior to that of the ASUS M4A89GTD PRO/USB3. There are no options to control the CPU cooler and system fans here. 

Well, the lack of such options in the BIOS of the Gigabyte 890GPA-UD3H is made up for by Windows-based utilities. Gigabyte's handy and functional EasyTune 6 tool is included with the mainboard for that.

  

This utility can overclock the CPU and graphics core from Windows and offers extensive hardware monitoring options. You can also use it to set up the operation of the CPU cooler.

Mainboards Specifications 

 

ASUS M4A89GTD PRO/USB3

Gigabyte 890GPA-UD3H

CPU socket

Socket AM3

Socket AM3

Chipset

AMD 890GX + AMD SB850

AMD 890GX + AMD SB850

Integrated graphics

ATI Radeon HD 4290

ATI Radeon HD 4290

128 MB DDR3-1333 Sideport Memory

128 MB DDR3-1333 Sideport Memory

Memory

4 x DDR3 DIMM

4 x DDR3 DIMM

Dual-channel DDR3-1067/1333/1600 SDRAM

Dual-channel DDR3-1067/1333/1600 SDRAM

Maximum capacity – 16 GB

Maximum capacity – 16 GB

Expansion slots

2 x PCI Express x16

2 x PCI Express x16

1 x PCI Express x4

3 x PCI Express x1

1 x PCI Express x1

2 x PCI

2 x PCI

 
Audio codec

Realtek ALC892 8-channel HD audio codec

Realtek ALC892 8-channel HD audio codec

Ethernet controller

Realtek RTL8111E Gigabit Ethernet

Realtek RTL8111D Gigabit Ethernet

Firewire controller

VIA VT6308

TI TSB43AB23

Additional ATA controller

JMicron JM361

Gigabyte GSATA2

USB 3.0 controller

NEC D720200F1

NEC D720200F1

Board size

ATX, 305x244 mm

ATX, 305x244 mm

Internal Interfaces

USB 2.0

8

8

IEEE-1394

1

2

Serial Port

1

1

Parallel Port

No

No

Floppy

No

Yes

Ultra-ATA 133

1

1

SATA 3.0

No

2 (with RAID support)

SATA 6.0

6  (with RAID support)

6 (with RAID support)

I/O Panel Connectors

USB 2.0

4

4

USB 3.0

2

2

IEEE-1394

1

1

Ethernet

1

1

eSATA

1

No

Analog audio

6

6

Digital audio

Optical SPDIF out

Optical SPDIF out

Video

Dual-link DVI, HDMI, D-Sub

Dual-link DVI, HDMI, D-Sub

 

Testbed and Methods 

We will benchmark the mainboards based on the AMD 890GX chipset in comparison with a mainboard based on AMD's previous integrated chipset, 785G. It is the Gigabyte MA785GT-UD3H. This mainboard has similar functionality like the two tested products and works with DDR3 SDRAM, too. 

The following hardware and software components are used in the test session:

We are going to carry out our performance tests using an external graphics card as well as the integrated Radeon HD 4290 graphics core. Therefore, there is a discrete graphics card Radeon HD 5870 among the testbed components.

Tests with Discrete Graphics

You cannot usually expect platforms that have the same CPU, memory and graphics card but different mainboards to differ much in performance. Indeed, as you can see, the three mainboards are very similar, the Gigabyte 890GPA-UD3H enjoying but a very small advantage over its opponents. Take note that both AMD 890GX based products are generally faster than the AMD 785GX-based Gigabyte MA785GT-UD3H.  

While the choice of a particular mainboard does not matter much in terms of system performance, it does influence the resulting power consumption of the computer. 

The diagrams show the total consumption of each computer measured “after” the power supply. It is the total of the power consumption of all system components. The PSU's efficiency is not accounted for here.

The ASUS M4A89GTD PRO/USB3 is the most economical solution among the three tested mainboards. When under load, the computer with this mainboard consumes about 17% less power than the same computer with the Gigabyte mainboard. It is clear that the key system components are powered by the ASUS M4A89GTD PRO/USB3 in a more efficient way.

Tests with Integrated Graphics

The new ATI Radeon HD 4290 graphics core based on the AMD 890GX chipset is claimed to be 12 to 13% faster in games than the graphics core integrated into the AMD 785G chipset. This could be expected since the AMD 890GX-based mainboards have a higher GPU frequency and a Sideport memory chip. 

We are more interested to check out the power efficiency of the new graphics core. 

The comparison of the Gigabyte cards suggests that the Radeon HD 4290 is not much more economical than its predecessor. No wonder as the AMD 890GX North Bridge is manufactured on the same 55nm tech process as the AMD 785G and has a TDP of 22 watts as compared to the predecessor's 15 watts. On the other hand, the ASUS M4A89GTD PRO/USB3 surprises us with its low practical power consumption again, but it is not due to the properties of the chipset. The good results are due to ingenious engineering solutions of ASUS's development team. 

CPU Overclocking 

We found some differences between our AMD 890GX-based mainboards when we checked out their overclocking potential. On the AMD 785G-based Gigabyte MA785GT-UD3H mainboard we compare the new mainboards with, our Athlon II X4 635 processor was found to be stable at a peak frequency of 3625 MHz. To achieve that frequency the CPU voltage was increased by 0.1 volts to 1.5 volts and the clock generator's frequency was lifted up from the default 200 to 250 MHz. The memory frequency was increased to 1666 MHz at that, which provoked no problems. The frequency multipliers for the integrated North Bridge and the HyperTransport bus were manually lowered from 10x to 8x so that the resulting frequencies were as close to the default ones as possible. 

Running a little ahead, we can say that both AMD 890GX-based mainboards easily coped with such overclocking. Moreover, they both improved that result somewhat, to our satisfaction. 

To be specific, the ASUS M4A89GTD PRO/USB3 could keep the Athlon II X4 635 stable at a clock generator's frequency of 253 MHz. It means that the CPU frequency was as high as 3668 MHz. 

The CPU voltage was set at 1.5 volts and we used 8x multipliers for the frequencies of the HyperTransport bus and integrated North Bridge. The memory frequency grew up to 1686 MHz then. 

The Gigabyte 890GPA-UD3H did not get as high as its opponent. At a clock generator frequency of 253 MHz, the mainboard did not pass our stability test. The system was stable at 251 MHz, i.e. at a CPU frequency of 3640 MHz. 

The rest of the voltages and frequency multipliers were set at the same values as with the other two mainboards. 

Thus, it is with the ASUS M4A89GTD PRO/USB3 that we reached the highest CPU frequency in our overclocking experiments. As for the overclocking potential of the AMD 890GX chipset in general, our tests suggest that it is no worse than that of the AMD 785G. We see no reason why the new chipset cannot be recommended to enthusiasts. 

The performance delivered by the overclocked mainboards can be seen in the next diagrams. 

The higher CPU frequency achieved with the ASUS M4A89GTD PRO/USB3 makes it the fastest platform in the performance tests. On the other hand, its advantage over the Gigabyte mainboard based on the same chipset is not too large. The difference is a mere 1-2%. 

The power consumption of these mainboards is quite a different story. Although the three tested mainboards allow to overclock the CPU without turning off Cool'n'Quiet technology, they behave differently at the increased CPU frequency and voltage.  

The ASUS M4A89GTD PRO/USB3 is still highly economical when idle. But when under high CPU load, the power consumption of the system with this mainboard grows up greatly and outruns that of the systems with the Gigabyte mainboards. This must be due to the ASUS mainboard's enabling its Load-Line Calibration feature which increases the voltages a little under high CPU load. Gigabyte's mainboards do not have such a technology and consume less power as the consequence. 

Radeon HD 4290 Overclocking 

Nearly every mainboard based on AMD's integrated graphics chipsets permit to overclock the integrated graphics core. And the two mainboards we are discussing here are no exception. You will find the options necessary to set the graphics core clock rate in their BIOS Setup. As our experiments suggest, the Radeon HD 4290 can indeed be overclocked well enough. If you additionally increase the voltage on the chipset's North Bridge, you can achieve a nearly 50% increase in terms of GPU clock rate. 

For example, when we increased the voltage on the AMD 890GX North Bridge by a mere 0.1 V above the default value, the integrated graphics core was stable at 1 GHz, which was 33% higher than the default frequency of 700 MHz. This result is not so unexpected, though. Mainboards based on the AMD 785G chipset are about as good at overclocking the integrated graphics core. For example, the one of the Gigabyte MA785GT-UD3H mainboard we use for the sake of comparison was quite stable at a clock rate of 950 MHz with the same voltage. 

However, the AMD 890GX-based mainboards we are discussing here can overclock not only the graphics core but also the frequency of the Sideport memory. This option is available in their BIOS. When the voltage on this chip of DDR3-1333 SDRAM was increased to 1.7 V, we managed to raise its frequency up to 1670 MHz on the ASUS M4A89GTD PRO/USB3 and up to 1640 MHz on the Gigabyte 890GPA-UD3H. 

This overclocking boosts performance in games by about 25%, which is quite rewarding. The diagrams below show the performance of the platforms when both the CPU and the integrated GPU were overclocked. It must be noted that the GPU overclocking has no effect on CPU overclocking, so the frequency of the Athlon II X4 635 processor in these tests is the same as in the CPU overclocking experiments described in the previous section. 

As you can see, the number of frames per second is more or less acceptable in today's popular games (at the lowest graphics quality settings, of course). 

Conclusion

Summing everything up, AMD's new chipset is a success. In our recent review, talking about the graphics part of the new Clarkdale processors, we supposed that Intel had a chance to take the upper hand on the market of integrated graphics solutions, but now we have to take back our words. Although AMD has not implemented any new technologies into its integrated graphics core and only increased the clock rate of the already available solution, the AMD 890GX is indeed the chipset with the fastest graphics core right now. 

Besides, the AMD 890GX has one more advantage in comparison with Intel's integrated graphics platform as it can work with any Socket AM3 processors. That is, it can work together with CPUs that have one, two, three, four or even six processing cores in systems of varying degree of computing performance. Intel cannot offer this flexibility in configuring your integrated platform since the new Intel HD Graphics core is located not in a chipset but inside the processors of the Clarkdale series. 

The AMD 890GX is interesting with its other capabilities, too. This chipset offers a full-speed PCIe 2.0 bus for the additional interface controllers and, thanks to the new South Bridge, natively supports Serial ATA 6 Gbps. In other words, mainboard makers can use the AMD 890GX to release modern products at the minimum cost of extra onboard controllers. This should make integrated platforms with Socket AM3 processors cheaper. 

That said, the AMD 890GX has such capabilities that can make it suitable not only for low-end computers. This chipset not only supports discrete graphics cards but also allows building CrossFireX configurations. So, mainboards based on the AMD 890GX chipset can be targeted at enthusiasts and the two products from ASUS and Gigabyte tested in this review are practical examples. 

The first mainboards on AMD's new chipset are at least equal to the previous-generation products and even superior to them in some respects. The support for new interfaces and technologies, good performance, compatibility with the upcoming six-core CPUs, and superb overclocking options - all this should attract users to AMD 890GX-based products. 

Choosing among the offerings from the leading mainboard makers, we'd recommend you to consider the ASUS M4A89GTD PRO/USB3 in the first place. Although not without some peculiarities, this mainboard has a lot of indisputable benefits such as a handy design, low power consumption, broad options to control system fans, the technology to unlock disabled CPU cores, and excellent CPU overclocking features. The relatively high price is the only reason why we cannot call this mainboard perfect. 

On the other hand, the AMD 890GX should not be considered at all if a low price is your priority because mainboards on the earlier AMD 785G chipset, which has but scarcely lower functionality, cost much less today. And this fact may prevent AMD's new and highly promising integrated chipset from getting really popular.