ASUS Radeon HD 7970 CrossFire

http://www.techpowerup.com/reviews/ASUS/HD_7970_CrossFire/1.html

AMD's Radeon HD 7970 was successfully launched on December 22 last year as the fastest single GPU graphics card in the world. Until today only reviews of AMD cards were allowed, so today we bring you a review of the ASUS Radeon HD 7970 in multi GPU CrossFire mode.

If you haven't done so yet, check out our single card HD 7970 for the architecture update and card photos.

Instead of just placing a simple sticker on their HD 7970, ASUS has decided to go with a little bit more effort. The company has put a 3D shaped metal "cap" on the middle section of the card, where usually an ATI red shines. As you can see from the picture above, the ASUS design looks mighty good and clearly improves the looks of the Raden HD 7970. Great job ASUS! For overclockers ASUS includes their own GPUTweak software which supports the HD 7970 for overclocking, voltage control and GPU information.

In terms of specs, the card comes at the same clock speeds as the AMD reference design, running at 925 MHz core and 1375 MHz memory. Pricing is unchanged too, $550 for a single card, twice that, $1100 for the dual card CrossFire combination we test in this review.

ASUS Radeon HD 7970 CrossFire Market Segment Analysis
	GeForce GTX 560	GeForce GTX 560 Ti	GeForce GTX 560 Ti 448 C	Radeon HD 6950	GeForce GTX 570	Radeon HD 6970	GeForce GTX 580	Radeon HD 7970	Radeon HD 6990	GeForce GTX 590	ASUS HD 7970 CrossFire
Shader Units	336	384	448	1408	480	1536	512	2048	2x 1536	2x 512	2x 2048
ROPs	32	32	40	32	40	32	48	32	2x 32	2x 48	2x 32
Graphics Processor	GF114	GF114	GF110	Cayman	GF110	Cayman	GF110	Tahiti	2x Cayman	2x GF110	2x Tahiti
Transistors	1950M	1950M	3000M	2640M	3000M	2640M	3000M	4310M	2x 2640M	2x 3000M	2x 4310M
Memory Size	1024 MB	1024 MB	1280 MB	2048 MB	1280 MB	2048 MB	1536 MB	3072 MB	2x 2048 MB	2x 1536 MB	2x 3072 MB
Memory Bus Width	256 bit	256 bit	320 bit	256 bit	320 bit	256 bit	384 bit	384 bit	2x 256 bit	2x 384 bit	2x 384 bit
Core Clock	810 MHz	823 MHz	732 MHz	800 MHz	732 MHz	880 MHz	772 MHz	925 MHz	830 MHz	607 MHz	925 MHz
Memory Clock	1002 MHz	1002 MHz	950 MHz	1250 MHz	950 MHz	1375 MHz	1002 MHz	1375 MHz	1250 MHz	855 MHz	1375 MHz
Price	$180	$210	$290	$250	$330	$340	$500	$549	$700	$750	$1100

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.

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. An optimized fan profile is also one of the few things that board vendors can do to impress with reference designs where they are prohibited to make changes to the thermal solution or components on the card.

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 Crysis 2 as a standard test representing typical 3D gaming usage because it offers: - very high power draw - high repeatability - is a current game that is supported on all cards due to its DirectX 9 nature - drivers are actively tested and optimized for it - supports all multi-GPU configurations - test runs a relatively short time and renders a non-static scene with variable complexity.

Our results are based on the following tests:

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.
Multi-Monitor: Two monitors connected to the tested card, which use different display timings. 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: Crysis 2 at 1920x1200, Extreme profile, representing a typical gaming power draw. Average of all readings (12 per second) while the benchmark was rendering (no title/loading screen).
Peak: Crysis 2 at 1920x1200, Extreme profile, representing a typical gaming power draw. 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. On cards with power limiting systems we will disable the power limiting system or configure it to the highest available setting - if possible. We will also use the highest single reading from a Furmark run which is obtained by measuring faster than when the power limit can kick in.
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.

In our single card review of AMD's Radeon HD 7970 we were already impressed by the card's power consumption. The Crossfire combination can impress even more.

When using two or more HD 7970 cards in CrossFire without gaming, only one card will be running, while the other cards are in AMD's new ZeroCore power state, during which they consume only about 1 Watt of power and the fan is disabled.

Once you fire up a gaming session, the other cards in a CrossFire group will wake up and instantly be able to provide their full rendering power.