[W1zzard]

Introduction

AMD recently released their Radeon HD 6900 Series which delivers high-end 3D performance based around the new Cayman GPU. The new Series boasts improvements in power consumption while increasing performance over last generation. Most noteworthy, however, is the possibility to unlock a Radeon HD 6950 into a HD 6970 by a simple BIOS flash.

With the Radeon HD 6950 1 GB AMD introduces a new HD 6950 variant that is more cost effective than the 2 GB version. The price difference is about $40, just for 1 GB less memory, all other specs have remained the same. So the big question is: Will the reduced memory size affect performance?

	Radeon HD 6850	Radeon HD 5850	GeForce GTX 470	Radeon HD 6870	Radeon HD 5870	Radeon HD 6950	Radeon HD 6950 1 GB	GeForce GTX 570	GeForce GTX 480	Radeon HD 6970	GeForce GTX 580
Shader units	960	1440	448	1120	1600	1408	1408	480	480	1536	512
ROPs	32	32	40	32	32	32	32	40	48	32	48
GPU	Barts	Cypress	GF100	Barts	Cypress	Cayman	Cayman	GF110	GF100	Cayman	GF110
Transistors	1700M	2154M	3200M	1700M	2154M	2640M	2640M	3000M	3200M	2640M	3000M
Memory Size	1024 MB	1024 MB	1280 MB	1024 MB	1024 MB	2048 MB	1024 MB	1280 MB	1536 MB	2048 MB	1536 MB
Memory Bus Width	256 bit	256 bit	320 bit	256 bit	256 bit	256 bit	256 bit	320 bit	384 bit	256 bit	384 bit
Core Clock	775 MHz	725 MHz	607 MHz	900 MHz	850 MHz	800 MHz	800 MHz	732 MHz	700 MHz	880 MHz	772 MHz
Memory Clock	1000 MHz	1000 MHz	837 MHz	1050 MHz	1200 MHz	1250 MHz	1250 MHz	950 MHz	924 MHz	1375 MHz	1002 MHz
Price	$180	$260	$260	$240	$360	$275	$235	$330	$450	$370	$500

The Card

Visually AMD's HD 6950 1 GB looks exactly the same as the 2 GB variant, all changes were done under the hood.


The card requires two slots in your system.


The card has two DVI ports, one full size HDMI port and two mini-DisplayPort outputs. AMD's display output logic is clearly superior to what NVIDIA has to offer at this time. Vendors are free to combine six TMDS links into any output configuration they want (dual-link DVI consuming two links) - and use them all at the same time. AMD has also introduced DisplayPort 1.2 support with their new cards which allows the use of a DisplayPort hub to connect multiple monitors, or daisy chain them together.

An HDMI sound device is also included in the GPU. The HDMI interface is HDMI 1.4a compatible which includes Dolby TrueHD, DTS-HD, AC-3, DTS and up to 7.1 channel audio with 192 kHz / 24-bit output. The new revision also brings support for Blu-ray 3D movies which will become important later this year when we will see first Blu-ray 3D titles shipping.


You may combine up to four HD 69xx cards from any vendor in CrossFire.


Here are the front and the back of the card, high-res versions are also available (front, back). If you choose to use these images for voltmods etc, please include a link back to this site or let us post your article.

A Closer Look

AMD's heatsink uses a Vapor-Chamber Technology cooler with a large copper base. The thermal paste used is the same as on the HD 6990, a phase-change material that has the consistency of hard wax when cooled off but gets soft with higher temperatures.


The card has two 6-pin PCI-Express power connectors which are specified up to 225 W power delivery.


Like on the AMD HD 69xx reference designs, a BIOS switch is present which lets you select between the original BIOS and a backup BIOS in case something goes wrong with a BIOS flash. Combined with the HD 6950 to HD 6970 modding potential this makes an unbeatable combo because it's almost impossible that you screw up enough to end up with a $250 paperweight.


The GDDR5 memory chips are made by Hynix, and carry the model number H5GQ2H24MFR-T2C. They are specified to run at 1250 MHz (5000 MHz GDDR5 effective).


AMD is using a new voltage controller on their 1 GB card. While the HD 6950 / 6970 2 GB uses a Volterra VT1556, the 1 GB version uses a VT1586. Unfortunately this controller is not supported in any OC software - yet.


AMD's Cayman graphics processor is made on a 40 nm process at TSMC Taiwan. It uses approximately 2.64 billion transistors on a die area of 389 mm².

Test System

Test System - VGA Rev. 14
CPU:	Intel Core i7 920 @ 3.8 GHz (Bloomfield, 8192 KB Cache)
Motherboard:	Gigabyte X58 Extreme Intel X58 & ICH10R
Memory:	3x 2048 MB Mushkin Redline XP3-12800 DDR3 @ 1520 MHz 8-7-7-16
Harddisk:	WD Caviar Black 6401AALS 640 GB
Power Supply:	akasa 1200W
Software:	Windows 7 64-bit
Drivers:	GTX 590: 267.71 GTX 560: 266.56 NVIDIA: 266.58 HD 6990: 8.84.3 Beta 2 ATI: Catalyst 11.1
Display:	LG Flatron W3000H 30" 2560x1600

Benchmark scores in other reviews are only comparable when this exact same configuration is used.

• All video card results were obtained on this exact system with the exact same configuration.
• All games were set to their highest quality setting

Each benchmark was tested at the following settings and resolution:

• 1024 x 768, No Anti-aliasing. This is a standard resolution without demanding display settings.
• 1280 x 1024, 2x Anti-aliasing. Common resolution for most smaller flatscreens today (17" - 19"). A bit of eye candy turned on in the drivers.
• 1680 x 1050, 4x Anti-aliasing. Most common widescreen resolution on larger displays (19" - 22"). Very good looking driver graphics settings.
• 1920 x 1200, 4x Anti-aliasing. Typical widescreen resolution for large displays (22" - 26"). Very good looking driver graphics settings.
• 2560 x 1600, 4x Anti-aliasing. Highest possible resolution for commonly available displays (30"). Very good looking driver graphics settings.

Aliens vs. Predator

Aliens vs. Predator is based on a merger of the Aliens and the Predators franchise: two legendary alien species that are in conflict with each other, fighting to the death with human marines caught in between. The first person shooter game was developed by Rebellion Studios, who also developed the first AVP PC title and released in February 2010. It was one of the first DirectX 11 games with support for new features like Tesselation, which is why AMD heavily promoted it at the time of their DX 11 card launches. We used the AVP benchmark utility with tesselation and advanced DX11 shadows enabled.

Battlefield: Bad Company 2

Battlefield: Bad Company 2, released in March 2010 by Electronics Arts, is the most successful DirectX 11 title so far. Even though it contains a full single-player campaign during which the player has to work with a squad to secure a secret weapon, the game is most well known for its fast paced, exciting multiplayer squad action. Thanks to a CPU-based Havok physics engine and skillful use of scripting, the game has destroyable objects, vegetation and terrain without requiring NVIDIA PhysX.
We tested the truck chase scene of the second single-player mission at maximum settings with DirectX 11 enabled.

BattleForge

BattleForge, a card based RTS, is developed by the German EA Phenomic Studio. A few months after launch the game was transformed into a Play 4 Free branded game. That move and the fact that it was included as game bundle with a large number of ATI cards made it one of the more well known RTS games of 2009. You as a player assemble your deck before game to select the units that will be available. Your choice can be from forces of Fire, Frost, Nature and Shadow to complement each other.
The BattleForge engine has full support for DX 9, DX 10 and DX 10.1, we used the internal benchmark tool in DirectX 11 mode to acquire our results.

Call of Duty 4

Call of Duty 4 is a first-person shooter that is built on the award winning Call of Duty Series. It is the first version to play in modern times. In a near-future conflict between the United States, Europe and Russia you get to play as a United States Marine and a British SAS operative. The engine is Infinity Ward's own creation and has true dynamic lighting, depth of field, dynamic shadows and HDR. Even though the game plot is scripted you will find yourself in intense battles, often working together with computer controlled team mates.

Call of Juarez 2

Call of Juarez 2: Bound in Blood is a prequel to the first Call of Juarez game which was one of the first DX10 titles available on the market. This time the plot evolves around two brothers, before each mission you may pick one to play. Your choices affect the game play since both characters have different ways of handling situations and doing combat.
Call of Juarez 2 uses Techland's Chrome Engine 4 which adds Edge Anti Aliasing as one of the first engines on the market. Edge Anti Aliasing looks similar to normal AA but comes with a considerably reduced performance drop. However, due to the deferred shading design of Edge AA, normal AA can't be used on top of it.

Civilization 5

Sid Meier's Civilization V (or Civ 5 in common jargon), is the latest addition to the franchise of masterfully-crafted realtime strategy games that let you play God to a nascent civilization of your choice all the way up to the space-age. Civilization V uses large 3D worlds that are procedurally-generated, and takes advantage of hardware tessellation features offered by DirectX 11 to exponentially step up complexity of cities, models, terrains, and objects. It is also expected of this generation of GPUs to handle the larger texture loads that come with the eye-candy.

Crysis

After the tremendous success of Far Cry, the German game studio Crytek released their latest shooter Crysis in 2007. The game was by far the most hyped and anticipated game in 2007, the forums were full of "Can my system run Crysis?" threads because of the high hardware requirements of this game. Just like in Far Cry the plot evolves on a small island with a thick and richly detailed jungle world. A lot of attention has been given to small details like correct physics. For example when you fire on a tree trunk, it will shatter and the tree will fall over leaving a stump behind. Enemies in a car can be stopped by shooting the tire of the car. The game graphics are by far the best ever seen in a PC game so far, yet the game still runs well on most computers.

Formula One 2010

F1 2010 is an official implementation of the Formula One 2010 season with accurate teams, drivers and cars. One highlight of the game are the extensive realism options and the detailed weather effects. You pick a driver and get to race over several seasons, constantly improving your skill and trying to impress the big teams to score a contract with them to enjoy the faster car to race for the world championship. The game is based on an improved Dirt 2 engine and features the latest in DirectX 11 technology. We used the highest details setting for our testing.

Far Cry 2

Four years after the success of Far Cry, Ubisoft has published the sequel called Far Cry 2. While the first part was set on an island, Far Cry 2 takes you deep into Africa with game play that resembles Grand Theft Auto much more than the original Far Cry, which was a classical 3D shooter. Ubisoft engineered a completely new 3D engine called "Dunia" which offers a large amount of popular features like DirectX 9 and DirectX 10 support, destructible environments, physics and non-scripted AI while not being as much of a resource hog as Crytek's CryEngine. We tested the Ranch Medium level at DirectX 10 with highest details.

Tom Clancy's HAWX

Tom Clancy's H.A.W.X. is one of the very few recent flight simulator games on the market. Being a console conversion it emphasizes "flight" more than "simulator". It is set in a near future in which private military companies have begun fighting conflicts for nations with their own military gear. You are playing an elite pilot who was recruited by such a private company. During the game you get to fly over 50 different aircrafts, ranging from the MIG 21 to the mighty F22 Raptor. One notable feature of its engine is the use of GeoEye satellite imagery for terrain generation which offers one of the most realistic incarnations of battlefield terrain available today.

Metro 2033

Metro 2033 is a first-person shooter game that is set in a post apocalyptic Moscow - as the name suggests inside the metro system. You will fight mutants or other humans who like to take away your shelter. The game has many gameplay elements similar to STALKER, also the engine has similar features. This is because two STALKER engine programmers left GSC Game World and started their own company which is now making Metro 2033.
The engine has support for all the latest eye candy like DirectX 11 and Tesselation. Unfortunately it leaves a less than optimized impression, making it a candidate to surpass Crysis for the highest hardware requirements. We tested in DirectX 11 mode with details set to "Very High".

Unreal Tournament 3

The fourth game in Epic's highly successful Unreal Tournament Series is simply called Unreal Tournament 3. It is based on the Unreal 3 engine which is a major step forward from the previous engine. The game principle is centered about an arena style gameplay where several contestants try to reach a certain kill count or capture a flag for example. For its time, the graphics were top notch, with large and detailed textures. Unreal Tournament 3 is an important benchmark because its engine has been used in a large number of other titles, and there are even some in development using it. One major drawback of the way the engine is designed is that there is no support for Anti-Aliasing.

World of Warcraft: Cataclysm

World of Warcraft is the most successful massively multiplayer online game in the world with far over 12 milion monthly subscribers. The game is centered around the epic battle between the Horde and Alliance factions with many other races getting involved in a long and complex story line. Even though it has been released in 2004, Blizzard has always added incremental improvements to the graphics, especially with new expansions. One key success of World of Warcraft is that it will run on a large number of slower systems, but also delivers a decent graphics experience on high-end systems. We tested in DirectX 11 mode with details set to "Ultra".

3DMark 11

3DMark 11 is the very latest from the house of Futuremark, which has given out some of the most comprehensive benchmark applications for PC enthusiasts and gamers. 3DMark 11, as the name might probably suggest, makes use of Microsoft DirectX 11 API, and puts every feature at its disposal to use, creating astonishingly-realistic visuals. In the process, it evaluates DirectX 11 compliant GPUs, and lets gamers know what to expect from games from the near future that make use of the API, in terms of visual realism. The tessellation and depth of field tests are particularly of interest here.

Unigine Heaven 2.0

Unigine Heaven was one of the first demos that supported DirectX 11. Heaven is a technology demonstration for Unigine engine which supports DirectX 9 through 11 and OpenGL too. Version 2.0 adds more scenes and optionally more complex tesselation features. While there is some controversy surrounding the benchmark whether it is an accurate representation of what to expect from future games in regards to DirectX 11 we still chose it as test to get an insight into potential future gaming.

Power Consumption

Cooling modern video cards is becoming more and more difficult, especially when users are asking for quiet cooling solutions. That's why the engineers are now paying much more attention to power consumption of new video card designs.

For this test we measure power consumption of only the graphics card, via PCI-Express power connector(s) and PCI-Express bus slot. A Keithley Integra 2700 with 6.5 digits is used for all measurements. Again, the values here reflect card only power consumption measured at DC VGA card inputs, not the whole system.

We chose 3DMark03 Nature as a standard test representing typical 3D usage because it offers: - very high power draw - high repeatability - is a standard benchmark that is supported by all cards - drivers are actively tested and optimized for it - supports all multi-GPU configurations - easy to obtain - fairly compact in size - test runs a constant duration and renders a non-static scene with variable complexity just like any normal game.

The four result values are as following:

• Idle: Windows 7 Aero sitting at the desktop (1280x1024 32-bit) all windows closed, drivers installed. Card left to warm up in idle until power draw is stable.
• Average: 3DMark03 Nature at 1280x1024, 6xAA, 16xAF. This results in the highest power consumption. Average of all readings (12 per second) while the test was rendering (no title screen).
• Peak: 3DMark03 Nature at 1280x1024, 6xAA, 16xAF. Highest single reading during the test.
• Maximum: Furmark Stability Test at 1280x1024, 0xAA. This results in a very high non-game power consumption that can typically be reached only with stress testing applications. Card left running stress test until power draw converged to a stable value.
• Blu-ray Playback: Power DVD 9 Ultra is used at a resolution of 1920x1200 to play back the Batman: The Dark Knight disc with GPU acceleration turned on. Playback starts around timecode 1:19 which has the highest data rates on the BD with up to 40 Mb/s. Playback left running until power draw converged to a stable value.

All across the board, in all our tests, we see massively increased power consumption of the HD 6950 1 GB vs. the 2 GB variant. This comes as a huge surprise as typically less memory at same clocks means lower power consumption. Not 35 W more! Failed, AMD.

I see several possible explanations for this. First, in idle the card does not go to 0.9 V like the 2 GB version but runs at 1.1 V, same for Blu-ray: 1.01 V vs. 1.16 V and 3D: 1.11 V vs. 1.19 V. Another reason is that the card runs a few °C hotter with 89°C which is over 10% more than the 80°C we saw on the 2 GB reference design. A silicon chip running at a higher temperature will always require more power to do the same thing. Last but not least, it is possible that the changes in the voltage regulation design resulted in another increase in power consumption.

Fan Noise

In the past years users would accept everything just to get more performance. Nowadays this has changed with people being more aware of the fan noise and power consumption of their graphic cards.
In order to properly test the fan noise a card emits we are using a Bruel & Kjaer 2236 sound level meter (~$4,000) which has the measurement range and accuracy we are looking for.


The tested graphics card is installed in a system that is completely passively cooled. That is passive PSU, passive CPU cooler, passive cooling on the motherboard and Solid-State HDD.
This setup allows us to eliminate secondary noise sources and test only the video card. To be more compliant with standards like DIN 45635 (we are not claiming to be fully DIN 45635 certified) the measurement is conducted at 100 cm distance and 160 cm over the floor. The ambient background noise level in the room is well below 20 dbA for all measurements. Please note that the dbA scale is not linear, it is logarithmic. 40 dbA is not twice as loud as 20 dbA. A 3 dbA increase results in double the sound pressure. The human hearing is a bit different and it is generally accepted that a 10 dbA increase doubles the perceived sound level. The 3D load noise levels are tested with a stressful game, not Furmark.

In idle, fan noise of the HD 6950 1 GB is roughly the same as on the 2 GB card. Under load however, possibly due to the higher operating temperatures, the fan is noisier. Overall I find 41 dbA under load too noisy for a card in this performance class.

Performance Summary

To create this graph we took all performance results of the five resolutions we tested, threw them together and calculated the relative performance of each card, compared to our review sample. In a sixth graph we also combined all tests in all resolutions to calculate the total relative performance of the review sample. Cards that do not support DX11 were given a score according to their performance in all other non-DX11 tests, which means cards were not penalized for not having DirectX 11 support.

Performance per Watt

This graph was created by taking the relative performance numbers and putting them in contrast to the average power consumption results.

Performance per Dollar

If you are looking for the best bang for the buck, then you will love this graph. We looked up the current USD price of each card on the popular online shop Newegg and used it and the relative performance numbers to calculate the Performance per Dollar Index.

Overclocking

To find the maximum overclock of our card we used a combination of GPUTool and our benchmarking suite.
The overclocks listed in this section were achieved with the default fan and voltage settings as defined in the VGA BIOS. Please note that every single sample overclocks differently, that's why our results here can only serve as a guideline for what you can expect from your card.



Overclocks of our card are 930 MHz core (16% overclock) and 1470 MHz Memory (18% overclock). Quite impressive, this is even higher than what we could get out of our full HD 6970 which clocked in at 915 / 1445 MHz. This nice overclocking potential will come in handy when modding this card to a full HD 6970, as the modified card will have no problems running full HD 6970 clock speed.

Overclocked Performance

Using these clock frequencies we ran a quick test of Call of Duty 4 to evaluate the gains from overclocking.


Actual 3D performance gained from overclocking is 14.4%.

Temperatures

Temperatures in idle are fine, but load temperatures seem pretty much at the limit for what I could consider acceptable. Unfortunately fan noise is quite high as well.

Clock Profiles

Modern graphics cards have several clock profiles that are selected to balance power draw and performance requirements.
The following table lists the clock settings for major performance scenarios and the GPU voltage that we measured. We measure on the pins of a coil or capacitor near the GPU voltage regulator.

	Core Clock	Memory Clock	GPU Voltage (measured)
Desktop	250 MHz	150 MHz	1.15 V
Blu-ray Playback	500 MHz	1250 MHz	1.16 V
3D Load	800 MHz	1250 MHz	1.19 V

CCC Overdrive Limits
Core	840 MHz
Memory	1325 MHz

Value and Conclusion

	AMD's Radeon HD 6850 1 GB can be found online for around $235.
	Same performance as HD 6950 2 GB Can be modded to HD 6970 Great overclocking potential Dual BIOS switch Native full-size HDMI output Support for DirectX 11
	High power consumption, higher than HD 6950 2 GB Noisy fan under load Higher temperatures than on 2 GB version High power draw in Blu-ray playback CCC Overdrive limits too low Power draw limiter could complicate advanced overclocking DirectX 11 relevance limited at this time No support for CUDA / PhysX
8.9	It looks like AMD has listened to the countless requests for a cheaper HD 6950 card. With just 1 GB of memory, instead of 2 GB, the card retails for around $40 less than its big brother. Even though memory size might suggest otherwise, we have seen absolutely no evidence of reduced performance. In no game, not even in Metro 2033 or Crysis, and no, not even at 2560x1600. This means that 1 GB of video memory is still a viable choice for a high-end gaming card today. What surprised us however is the massively increased power consumption of the HD 6950 1 GB compared to the 2 GB version. In all our tests we see higher power draw, which seems to be caused by several factors, the most important being voltage and operating temperature. Temperatures of the card are even higher than on the 2 GB version, but still at safe levels. Due to higher power and temperatures, the fan has to work harder which means the card is noisier than it should be. Overall, what matters most is that AMD now has a real alternative to fight NVIDIA's GTX 560 in the $250 market segment. For budget oriented gamers the choice is now HD 6950 1 GB or GTX 560 Ti. Modding the card to HD 6970 also seems possible, making this a nice toy for tweakers and overclockers.