ASUS Radeon EAH6850 DirectCU Review

Author: Chris Ledenican
Editor: Howard Ha
Publish Date: Tuesday, November 16th, 2010
Originally Published on Neoseeker (
Article Link:
Copyright Neo Era Media, Inc. - please do not redistribute or use for commercial purposes.

The AMD Radeon 6800 series is still very new to the market, but we are already starting to see non-reference cards hit retail shelves. We have already tested an overclocked HD 6870, however all the cards in the series that have made it to our labs have thus far used the reference cooler. The ASUS model we are going to be looking at in this review uses a DirectCU cooler featuring dual heatpipes that make direct contact with the GPU. This is a design that ASUS has been using on multiple graphics cards lately, and is found in both AMD and NVIDIA flavors. The cooler is very efficient and aids in the overall cooling of the GPU, and VRM area. This allows the DirectCU series to support Voltage Tweak, which gives the owner of the card direct control of the voltage levels. This can enhance the overclocking capabilities of the card and in turn improve performance via additional overclocking headroom.

The ASUS EAH6850 DirectCU also includes a small factory overclock, but at only 15MHz the additional clock speeds might not yield a significant return. However, there is no price mark-up for this modest increase, so this model does not carry a higher premium than reference models. Also, most owners of the EAH6850 will purchase this specific model for the improved overclocking through the voltage control options, and not necessarily for the factory clock settings. With features such as improved cooling, Voltage Tweak and a very affordable price, this could be a card that appeals to the mainstream and enthusiast market.

In this review we will compare the EAH6850 against the current competition and see how it fairs at both standard and overclocked settings.


Graphics Engine AMD Radeon HD 6850
Bus Standard PCI Express 2.1
Video Memory DDR5 1G
Effective Memory Bandwidth 256-bit
Engine Clock
790 MHz
Memory Clock
4000 MHz (1000 MHz DDR5)
Memory Interface
CRT Max Resolution
2048 x 1536
DVI Max Resolution
2560 x 1600
D-Sub Output
Yes x 1 (via DVI to D-Sub adaptor x1)
DVI Output
Yes x 1 (DVI-I), Yes x 1 (DVI-D)
HDMI Output
Yes x 1
HDCP Support
Adaptor/Cable bundled
1 x DVI to D-Sub adaptor
1 x CrossFire cable
1 x Power cable
Software Bundled
ASUS Utilites & Driver
ASUS Features
DirectCu Series
The card size is 10.24" x 4.84" inches

The ASUS EAH6850's packaging uses an image of a dark knight charging into battle to portray the gaming potential of the HD 6850 graphics card. Along with this strong image, the package illustrates the included features of the graphics card and a large icon that highlights the Voltage Tweak feature. Overall the box is flashy and should be eye-catching to both hardcore and casual gamers.

The inner packaging, like the outer, is more stylish than that of a standard cardboard box. Instead of a simple brown box, ASUS has opted for an attractive black coating that carries the companies logo on the front. Inside the box are the graphics card and accessories, which are tucked away in their own separate compartments. This will prevent any damage from occurring to the components while the box is being transported.

The accessories that come with the EAH6850 consist of a 6-pin power adapter, manual, drivers & utilities disc, CrossFire connector, DVI to VGA adapter and a Speed Setup guide. ASUS has also included a CD/DVD wallet that can hold up to 16 discs.

The ASUS EAH6850 is the first 6800 series graphics card that we have tested to date with a non-reference cooling solution. The EAH6850 uses ASUS"s DirectCu cooler which uses dual heatpipes that make direct contact with the GPU. ASUS states this design is more efficient than the reference cooler and can improve cooling by up to 20%. The improved cooling will be essential when over-volting the card, and will directly affect the overclocking potential. The cooler does extend past the end of the PCB though, increasing the length of the HD 6850 to 10.24 inches. Additionally, the cooler has set of three red stripes running along the bottom half. This is obviously a nod to the AMD color scheme, as ASUS uses green stripes on their AMD products with the same cooler.

The back of the PCB is similar to reference models, but the EAH6850 is printed on a solid black board and curiously there are two sets of soldering points for the 6-pin power connector. This could leave one to think ASUS is working on a highly overclocked HD 6850 that exceeds the maximum TDP, but the more logical answer is that they are going to be using the same PCB for their EAH 6850 and 6870 models.

Like other graphics cards in the 6800 series, the EAH6850 supports only supports dual card CrossFire. Still, the amount of performance that is achievable by combining two of  6850's can rival the high-end HD 5970 in some games. Two HD 6850's will also cost just over the $350 mark.

The rear I/O options on the EAH6850 are another area where ASUS departed from the reference design. Instead of using two Mini-DisplayPorts, the EAH6850 uses a single standard-sized DP port. This reduces the connection options, but the HD 6850 is designed as a budget graphics card and most people in this market do not utilize multiple monitors. Next to the DP port is an HDMI 1.4a port which utilizes the latest HDMI technologies, and supports AMD's HD3D video and full HD audio. There are also dual DVI ports, and just like other cards in the HD 6800 series, one is DL-DVI and the other SL-DVI.

Even with the lack of dual Mini-DisplayPorts, Eyefinity would be easy to utilize with this model via the DVI ports and DP port.

The ASUS EAH6850 uses a direct contact cooler that has dual heatpipes to transfer heat. The two heatpipes are 8mm in size and are flattened at the base to ensure they make proper and even contact with the GPU. This approach is very efficient and should aid in the overall cooling capacity. To improve cooling, ASUS has included a thin metal heatsink on the VRM. Missing, however, is a method to cool the memory chips, but since they are not a really hot zone this is acceptable. The most important factor here is that the VRM and GPU remain under the max thermal threshold after the voltage level is increased. The reason for this is that the increased voltage will raise the temperature of both the VRM and GPU, and the cooling will have to be able to prevent the card from becoming unstable, eliminating any risk of damage.

The heatsink on the EAH6850 essentially consists of three separate parts: the heatsink, heatsink cover and the fan. We have looked at the bottom of the heatsink and explained the dual heatpipes, but the top of the cooler is just as essential to the cooling. The top of the heatsink is a large finned array where the heat is separated and finally exhausted out. The design of this cooler is different than the reference design in the manner it exhausts the air; the reference cooler removes all the hot air out of the case, whereas the EAH6850 will circulate the hot air into the case. There is always a chance other components can be effected by the excess heat, but if the cooler works as it should, any negative impact should be minimal.

The fan is 75 mm and uses a 4-pin PWM fan connector that will allow the card to regulate the fan's rotation depending on the internal temperature of the core.

For the most part the ASUS EAH6850 uses the reference specifications of the HD 6850, however the core clock is slightly increased on this model. The reference HD 6850 at default settings has a clock speed of 775MHz, whereas the EAH6850 comes clocked at 790MHz. The 15MHz increase is very small and should only account for an additional one or two frames per second, if any. Outside of the slight factory overclock, the EAH6870 uses the same Barts chip that is fabricated using a 40nm process, is 255mm² in size and has 1.7 billion transistors. The core packs in 960 stream processors, 32 ROPs and supports a 256-bit memory interface. The card also includes 1GB of GDDR5 memory that is clocked at 1000MHz (4000MHz effective).



Since the EAH6850 gives the user direct control of the voltage level supplied to the card, it is easy to overclock this model beyond the limitations of the reference model. Of course the temperature of both the VRM and GPU are directly related to the voltage being directed through them. This is the reason the EAH6850 uses a very robust cooling solution. To overclock, I used the ASUS Smart Doctor utility which is included on the drivers disc. I started small, and in the beginning raised the frequencies in increments of 10MHz, until stability was exceeded. At this point I raised the voltage and again adjusted the clock speeds in increments of 10MHz. After an hour or so of fiddling around with adjusting the speeds and running stability programs, I was able to max out the GPU clock speed at 1000MHz. This is actually very impressive, as this is high-end of the 6800 series overclocking capabilities, and I have only found a few HD 6870's to be stable at 1000MHz. The memory on the other hand overclocked similarly to the reference model and was capable of reaching frequencies of 1167MHz.

(Click me)

Hardware Configuration:


All the ATI cards released prior to the 6800 series will be tested using AMD's Catalyst 10.8 drivers, while the NVIDIA graphics cards will be tested using their 260.89 drivers. Both the HD 6870 and HD 6870, however, will be tested with AMD's latest 10.10 drivers release.

Benchmarks DX11:

Benchmarks DX10:

All benchmarks were performed at resolutions of 1280x1024, 1680x1050, 1920x1200 and 2560x1600. Vsync is disabled in the control panel and AA is set to x4 with AF set to x16. The only benchmark performed with lower AA and AF is Street Fighter IV, which showed better scaling when AA and AF were set to 0.


MSI's Kombuster will be used to gauge the power requirement and temperature of the graphics cards. The program applies a very heavy load to the GPU and as such will push the card beyond that of a game or benchmark. For the minimum temperature and power consumption the system will be left in an idle state for 15 minutes and for load Kombuster will be left on for 15 minutes.

Comparison Specifications:

AMD Radeon HD 6870
AMD Radeon HD 6850
ATI  Radeon
HD 5750
ATI Radeon HD 5770
ATI Radeon HD 5830
ATI Radeon HD 5870
Processing Cores
Core Clock
Memory Clock
Memory Interface
Memory Type
Fabrication Process

3DMark Vantage is the stunning sequel to 3DMark 06. Futuremark's benchmarking programs have always been at the center of every bragging match. The best way to show that you've got the greatest gaming rig, is to show that you've got the highest 3DMark score. Vantage does just that. It puts your system through a series of strenuous tests, and provides you with a score to brag about!

The overall 3DMark Vantage score might not seem overly impressive as the EAH6580 is near the bottom of the chart, but when looking at the score in the context of this card being a replacement for the HD 5700 series, it shows in a much better light. Once overclocked, the EAH6850 surpasses the HD 5830 which was part of the high-end Cypress series graphics cards.

Unigine Heaven became very popular very fast, because it was one of the first major DirectX 11 benchmarks. It makes great use of tesselation to create a visually stunning...heaven.

The EAH6850 perfoms execeptionally well in Unigine and at stock sits right between the perfornace of the GTX460 and GTX470. After overclocking the card, performance is increased to nearly match the HD 6870.

Aliens vs Predators is a DX11 Benchmark that runs though a scene straight out of the classic 80’s movie, Aliens. Since it uses DX11, it can often be more than a graphics card can handle.

Aliens vs Predtor is another example of the EAH6850 not being the fastest card avaible, but given its price range the performance is very good. In this benchmark the EAH6850 was able to achieve a higher frame rate than the HD 5830 and was ahead of the GTX 260 at the overclocked settings.

Metro 2033 puts you right in the middle of post apocalyptic Moscow, battling Mutants, rivals and ratio-active fallout. The game is very graphics intensive and utilizes DX11 technology, making it a good measure of how the latest generation of graphics cards performs under the new standard.

The EAH6850 kept a smooth frame rate in Metro 2033 all the way up to the 2560x1600 resolution. Impressive for for a $140 graphics card, and even more so when it performs better than the HD 5870 after its frequencies are increased.

Street Fighter 4 doesn’t necessarily push a graphics card to the limits, but it is a good benchmark to gauge the overall performance. This test is run at default settings to show the best scaling possible.

The EAH6850 places in between the HD 5830 and HD 5870 in Street Fighter IV.

Batman: Arkham Aslyum mixes extraordinary visuals with great gameplay, in order to make an excellent benchmark. It's not a stressful as Crysis, but it can still push cards to their limits.

While not the fastest graphics card in this test, the EAH6850 was able to achieve 59 FPS at the highest resolution.

Crysis Warhead is one of the most graphically intensive games on the mainstream market. It's graphically breathtaking, and can bring any system crashing to it's knees.

At stock the EAH6850 perfomred better than the 1GB GTX 460, and came close to surpassing the HD 5870 once overclocked.

Call of Duty is one of the most successful game franchises of all time and Modern Warfare 2 is the latest iteration in the series. The games combine modern-day settings and locations with jaw-dropping graphics and explosions.

Yet another good showing the EAH6850, and again it is very close to the perfomance level of the HD 5870.

Darkest of Days puts the player in historic battles to ensure the survival of key figures from the past. It is a very interesting concept and the use of real life conflicts keeps the title engaging. The in-game options does not allow PhysX to be disabled, so it can often favor NVIDIA graphics cards over those from ATI.

The EAH6850 is able to achieve playable frame rates all the way up to 2560x1600.

Resident Evil V is the newest installment of the Resident Evil series. The game comes with a built in benchmark that features a bunch of zombies walking around the center of a village. Believe it or not this seemingly simple benchmark can push video cards way out of their comfort zone!

The ASUS card places just under the GTX 460 before overclocking, and nudges just ahead of it once the clock speed boost is applied.

Just Cause 2 places you in Panau, Southeast Asia as Agent Rico Rodriguez. The game is a third-person shooter that pits you against countless enemies with the opportunity for plenty of environment destruction. With explosions and gun fire galore, this game is perfect for testing out the latest hardware.

In Just Cause 2 the EAH6850 doesn't quite reach the performance level of the GTX 460, but it does maintain its dominance over the HD 5830.


To measure core GPU temperature, MSI's Kombustor was used. The idle temperature was taken after leaving nothing running for up to 15 minutes. The load temperature was taken 15 minutes after starting Kombuster for Multi-Core graphics cards.

Prior to increasing the voltage level, the ASUS EAH6850 maxed out at only 66°C under full load. Very impressive, and this shows the power of the DirectCu cooler design. After the voltage was increased, the temperature spiked and maxed out at nearly 89°C. This was with the fan set to auto though, but even so the rotation was around 80% due to the PWM controller. With the fan at 100% the temps did drop 5°C, but the noise at that level was loud and might not be suitable for daily use.


Power Usage:

To measure power usage, a Kill A Watt P4400 power meter was used. Note that the above numbers represent the power drain for the entire benchmarking system, not just the video cards themselves. For the 'idle' readings we measured the power drain from the desktop, with no applications running; for the 'load' situation, we took the sustained peak power drain readings at the end of a 30 minute Kombustor run.

The EAH6850 has a slighly increased GPU clock speed which accounts for the extra voltage at stock. After overclocking and raising the voltage, there is a 48W spike in the power usage, which is the cause of the temperature increase.



When comparing the EAH6850 DirectCU model to the multitude of 6850 graphics cards on the market, it definitely stands out as a fine example of why we all love non-reference cards. The improved DirectCU cooling solution used by ASUS greatly reduced the operating temperature of the GPU, and even when under full load over a 20 minute time frame it managed to keep the core under 70°C. Additionally, the fan is much quieter than the blower fan on a reference models when set at low RPMs. It did still get quite loud in the higher RPM settings, but like the lower RPM settings, the DirectCU fan is much quieter than the reference card's at high rotation.

The improved cooling allows ASUS to include their Voltage Tweak option with this model. Essentially this enables direct control of the voltage level of the graphics card, which amounts to more power being supplied to the GPU, giving way to a higher overclocking ceiling. In my tests the EAH6850, with the voltage increased to 1.35V, was able to reach a stable clock speed of 1000MHz. This is no small feat for the 6850 series, as most of the more expensive HD 6870’s are not even capable of consistently reaching the 1000MHz mark. At the 1000MHz frequency, the EAH6850 had noticeable frame rate improvements over the stock speed, which enhances the value of the graphics card; the $179 retail price seems even more impressive.

After over-volting the graphics card, the temperature spiked, and at times reached nearly 90°C. I was in the higher voltage tier and could have reduced the voltage to find a medium between temperatures and maximum the overclock, but for testing purposes I wanted to push the card to the max. Even though I stopped at the 1000MHz GPU clock speed, I found that the card is capable of overclocking to higher frequinces, but the ASUS Smart Doctor utility was capped at the 1000MHz level, so that was the point where I stopped.

In addition to the improved cooling and overclocking headroom, the EAH6850 comes with all of the latest AMD technologies. These consist of support of AMD’s HD3D technology, Eyefinity support, and improved Tessellation performance. All this and the EAH6850 still maintains a retail price of only $179.99 USD, making the ASUS EAH6850 one of the better 6850’s I have tested.


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