PowerColor, Sapphire, XFX HD 7950 Review

Author: Chris Ledenican
Editor: Howard Ha
Publish Date: Monday, January 30th, 2012
Originally Published on Neoseeker (http://www.neoseeker.com)
Article Link: http://www.neoseeker.com/Articles/Hardware/Roundups/PowerColor_Sapphire_XFX_HD_7950/
Copyright Neo Era Media, Inc. - please do not redistribute or use for commercial purposes.

While the reference Radeon HD 7950 is a great performer, there are going to be a host of custom SKUs from AIB partners available on day one. In this review we are going to be looking at three custom graphics cards from Sapphire, PowerColor and XFX. All three of the HD 7950 models we are going to be examining sport a robust dual fan thermal solution, overclocked frequencies and high quality components. These ingredients will not only help make each model faster than the reference card, but also improve the overall efficiency and lower the acoustic levels as well.

Throughout the review we are going to be examining the graphics cards alphabetically, so we start with the PowerColor PCS+. This card includes a heatsink utilizing large 8mm heatpipes, a pure copper base and dual 92mm fans. This heatsink design is advertised to keep the GPU up to 15% cooler and 20% quieter. In addition, the PowerColor model is overclocked to 880MHz and for improved efficiency sports a digital PWM solution, multi-phase design and ferrite core chokes.

Next up we have the Sapphire HD 7950, which comes overclocked at 900MHz and like the PowerColor model includes a robust dual fan thermal solution. The solution used by Sapphire is similar to what they have used on other recently released high-end graphics cards, as it includes a five heatpipe design paired with a copper base and dual PWM fans. However, to improve the efficiency even further, Sapphire has attached a heatspreader to the PCB which is designed to cool the on-board components such as the memory and VRM.

Last but not least, we have the XFX R7950 Black Edition. This graphics card is also overclocked by 100MHz, giving it a 900MHz GPU engine, along with a 3GB memory sub-system clocked at 1250MHz. The BE graphics card also includes signature XFX thermal technologies such as HydroCell, Double Dissipation and Ghost thermal technology. All of these serve to increase the thermal performance of the R7950 while lowering the noise output. The XFX R7950 also comes equipped with Durate professional grade components, which consist of solid capacitors, ferrite core chokes and a 2oz copper layer.

It doesn’t take Matlock to find the similarities in these graphics cards, as all three companies are pushing to improve the performance and thermal efficiency via high-quality on-board components, overclocked frequencies and robust thermal solutions. However, each company uses their own unique technologies and components to get the job done.

The PowerColor PCS+ HD 7950 comes packaged in a large box with the model number, memory interface, video output options and Eyefinity support listed up front. The back of the box is also chock full of information, but the panel is dedicated more to the unique features and components used by PowerColor.

The bundle that comes with the graphics cards includes a single CrossFire bridge, HDMI to DVI convertor, Mini-DisplayPort to Displayport convertor, DVI to VGA adapter along with the drivers disc and instillation guide. PowerColor has included a decent bundle with their PCS+ model, and is good for getting the card installed and supporting up to four displays out-of-the-box.

The PowerColor PCS+ HD 7950 itself is a slick piece of hardware that rocks a black and blue color scheme along the heatsink shroud, two centralized propeller fans and a large aluminum heatsink under the hood. Along with the exceptional visual flair, the PowerColor model has also been tweaked in the frequencies department, coming with a GPU engine clocked at 880MHz, an increase of 80MHz compared to the reference version. Additionally, since this graphics cards is based on the Tahiti Pro GPU it features 1792 stream processors. 32 Raster units, 112 texture units and a 3GB memory buffer running on a 384-bit interface.

Even while PowerColor has kicked up the clock speeds, the PCS+ still only requires two 6-pin power connectors instead of the 8+6 pin configuration on the HD 7970. Each connector is able to supply up to 75 watts of power to the board, so also unlike its older sibling the HD 7950 does not have a huge reserve of additional power to pull from once overclocked. Still, we were able to push the reference model beyond the 1GHz mark after tweaking the voltage level, so we are confident in this cards overclocking headroom despite the 225W voltage limitation.

Both of the power connectors are located at the back of the PCB and are positioned at a 90° angle. This will allow them to be easily installed even in cases where there is little clearance left after installation the graphics card itself. The connectors are also connected in close proximity to the power regulation units, which we will be looking at once we strip the card down to the PCB.

PowerColor, like the other cards we are examining, stayed true to the stock video output configuration. In all the card includes two Mini-DP connectors, a single HDMI 1.4a connector and a Dual-Link DVI connector. The two on-board Mini-DP ports use the 1.2 standard which allows them to support up to three monitors per port (via MST Hub) and also support AMD HD3D technology. The middle HDMI 1.4a connector also supports 3GHz speeds with frame packing. Essentially this allows the connection to run the frames faster, thus creating a smoother gaming experience. The HDMI and DP ports can also be paired together to support HD3D Surround which allows for stereoscopic 3D to be run across three displays.

PowerColor has gone with a custom PCB that includes what they have dubbed their Gold power kit. Basically PowerColor has increased the quality of the on-board components by using a digital PWM design, a 6+2+1 multi-phase layout and ferrite core chokes. According to PowerColor, by using these components the overall stability is increased by as much as 15%, while the digital PWM can increase the power efficiency up to 90%. What this means for the consumer is better efficiency, higher overclocking potential and a longer life span for the graphics card.

The PowerColor model also comes with the on-board BIOS toggle switch, so this card supports altering the BIOS for higher overclocking headroom, or improved stability and so on. This is an optional feature, so it is nice to see that most companies are including it because it can be a life saver when flashing the BIOS.

The heatsink on the PCS+ model also uses a custom design that allows it to operate up to 15% cooler than the reference model and 20% quieter to boot. PowerColor has done this by using large aluminum heatsink that has a copper base covering 100% of the GPU which allows it to pull the heat away evenly from the core. It also includes a 3pcs 8mm heatpipe design that can match the cooling efficiency of up to six 6mm heatpipes.

The heatpipes are also optimally positioned throughout the heatsink array by including two S-shaped pipes that connect to both the lower and upper portion of the heatsink, while a third U-shaped heat pipe is utilized to maximize the array and spread the heat evenly throughout the surface.

To top off the thermal solution, PowerColor has added a large shroud that optimizes the direction of the airflow and also includes two 92mm dual PWM fans (both sharing a single 4-pin fan connector). With these two fans the PCS+ can provide up to 60% more air flow throughout the array than a traditional 80mm fan design. This allows the fans to expediently exhaust hot air, keeping both the heatsink and core at optimal thermal levels.

Next up we have the Sapphire HD 7950 Overclocked Edition. This card, like others in Sapphire's arsenal, comes packaged in an 100% recycled box that has a glossy finish and lists most of the key features of the graphics card on the front. If of course also comes with a smoking hot 3D rendered model on the front, but unlike other versions this one is wearing a camouflage ski mask and Vietnam-era war helmet, and is packing heat.

Sapphire has included a rundown of technologies supported by the Tahiti Pro GPU on the back of the box, including the GCN architecture, 3GB GDDR5 memory interface, Eyefinity 2.0, CrossFireX, Gen PCIe 3.0, APP Acceleration, DirectX 11.1, HDM video/audio, and HD3D technology. Along with these listed technologies, Sapphire has also included a list of the various awards they have won over the years as well as a detailed description of the graphics card.

The bundle included with the Sapphire HD 7950 OC is impressive. In total you get two 4-pin to 6-pin power adapters, a CrossFireX bridge, drivers/utilizes disc, a 1.8 meter High Speed HDMI cable along with a mini-DP to DP and HDMI to DVI convertors.

Right off the bat we can see the heatsink used in conjunction with this graphics card is similar to the dual-fan 6000 series models Sapphire has recently released. In our testing this has proved to be a worthwhile thermal solution, so we fully expect it to be able to handle the 28nm Tahiti Pro GPU. In addition to the heatink, this is an overclocked SKU and Sapphire has pushed the core frequency from 800MHz to 900MHz, which is an increase of just over 11%. Like the other models, the Sapphire HD 7950 comes with 3GB of GDDR5 memory running on a 384-bit bus. The memory comes clocked at 1250MHz, giving this card the same 240GB/s memory bandwidth as the reference model.

Just like the previous card we looked at, the Sapphire HD 7950 is going to have a slightly higher TDP than the reference models simply because at 900MHz the core draws more power than it would at 800MHz. Still, we are looking at the stock power configuration, giving the card up to 225 watts of power which is roughly 20 watts more than the core should be using while under load. The two power connectors are both found at the back of the board, and angled to facilitate easier access to the connection points.

The video output configuration is the same as what we have seen on all the Tahiti Pro graphics cards examined thus far. This gives the card two mini-DP ports, a single HDMI port and a single DL-DVI output. The four available video outputs offer a ton of expansion including support for up to four displays via Eyefinity 2.0, HD3D support and single display resolutions of up to 2560x1600. Additionally, both the DP and HDMI ports are able to output a full HD audio signal with supporting independent audio per connection.

Sapphire is also using a custom PCB that that has high quality solid capacitors, a 6+1 phase design and a CHL8228G voltage controller. These are all designed to improve the overall efficiency and longevity of the graphics card, but to go a step further, Sapphire has also included a large heat-spreader that makes contact with the vital components on the PCB. The heat-spreader will keep the tempuratures of the memory and VRM in check to both improve stability and possibly increase the overclocking ceiling of the memory as well.

The thermal solution attached to the HD 7950 consists of a large aluminum array with five copper heatpipes. The base of the heatsink is also pure copper, with four stand-offs ensuring the base applies the proper amount of force to the GPU. Each heatpipe on the heatsink is positioned in different locations throughout the aluminum array. This distributes the heat throughout the array to improve efficiency and allows heat to dissipate more quickly.

The outer cover of the heatsink is designed to ensure the airflow is directed efficiently throughout the array, but it also includes mounting for the 90mm fans which are connected to a recessed area in the cover. Each fan utilizes a special dust repelling bearing that reduces any dust build-up, thus increasing the operational lifetime of the fans. Sapphire has also redone the blades with an impeller design that reduces noise output.

To ensure the fans rotate at the adequate level for the current operation, both fans are connected to a single 4-pin PWM fan header. This allows the fans to dynamically switch the RPM level in real-time, which in turn lowers the acoustics when the system is idle to ensure there will be ample airflow whenever the system is under load.

The packaging XFX ships their HD 7950 in is a little smaller than the others, but the card still comes with a decent bundle. It even comes with the Do Not Disturb door hanger which conveniently includes the card's activation code and part number. A CrossFireX bridge, HDMI to DVI convertor, driver, manuals and a Black Edition case badge are all included. On top of these, XFX has really crammed their box full of information from front to back,.

The XFX R7950 Black Edition graphics card is encased in a sleek heatsink shroud with dual fans on the front, a black strip down the center and a brushed aluminum finish. Overall the aesthetics are exceptional, and just a quick look is enough to have you hooked on the visual design.

Internally the XFX Black Edition graphics cards sports the same specifications as the Sapphire model. This gives the card a 900MHz GPU clock, paired with 1792 streaming processors, 112 texture units, 32 ROPs and of course it uses AMD's Generation Core Next architecture. The XFX BE model also comes with the same 3GB GDDR5 frame buffer, giving this card a substantial amount of memory bandwidth which will come in handy when playing games at high single display resolutions or Eyefinity.

As part of the Southern Islands family, the XFX R7950 BE comes equipped with PowerTune technology and Zero Core Power. Both of these technologies are an internal power management system that maximizes the performance of the board via dynamic power adjustment. Zero Core Power, however, takes this management to a new level by disabling the core during long idle periods, which can reduce the total power consumption down to just 3 watts. Also, since PowerTune works on a microsecond level, Core Power will not interfere with gaming as all the GPUs can become active again in just microseconds.

The XFX R7950 BE should also have a power rating of just over 200W, supplied to the card via dual 6-pin power connectors. So, just like the other cards in this review there should be around 20 watts (give or take) of headroom left over to push the core to the max.

The XFX R7950 uses the same video output configuration as all the other models we have looked at thus far. In total there are two Mini-DP connectors, a single HDMI 1.4a connector and a Dual-Link DVI connector. However, what is different is the XFX logo on the ventilation ports. This feature can be easily overlooked, but according to XFX the design actually lowers your card's temperature by up to 20% by increasing airflow by up to 200%.

Like the other models, the middle HDMI 1.4a connector supports 3GHz speeds with frame packing. Essentially this allows the connection to run the frames faster, thus creating a smoother gaming experience. The HDMI and DP ports both natively support HD3D and can also be paired together to support HD3D Surround which increases both the depth and field of view in games.

The XFX R7950 BE uses the same PCB layout as the other models, but the XFX model comes with XFX Ghost Thermal Technology, a HydroCell thermal solution, solid capacitors, ferrite cores and a 2oz copper PCB. The PCB also sports a CHL8228G voltage controller from the CHiL Semiconductor Corporation. Of course the PCB also includes 12 memory chips surrounding the Tahiti Pro graphics processor, dual 6-pin power connectors and two CrossFire connection points.Howeever, missing from this model is the dual BIOS toggle switch, making it appear as if XFX doesn't want anyone flashing this card.

The thermal solution used on the R7950 BE uses XFX Ghost thermal technology, along with a HydroCell heatsink and Double Dissipation fans. These technologies increase the thermal efficiency of the heatsink. Breaking it down by technology, the Ghost thermal feature allows air to pass through the heatsink directly to the PCB and core components, thus cooling more than just the GPU. The HydroCell technology on the other hand is a chamber based on the same principles as heat-pipe technology. A liquid coolant is vaporized at a hot surface, the resulting vapor is condensed at a cold surface then the liquid is returned to the hot surface. The recirculation process is controlled by a wick system.

The last piece of the thermal solution is the Double Dissipation fans, which offer up to three times more air flow in comparison to standard fans. Essentially this means the fans can produce more airflow at a lower decibel level, allowing them to kick out higher CFM while remaining quiet. The IP-5X fans block dust from entering the bearing to help increase the lifespan of the fans.

Overclocking:

Overclocking the three different graphics cards proved to be hassle free. Since we already knew the reference model was cable of scaling the core and memory clock speeds to 1000MHz and 1575MHz, respectively, we started with a base clock of 1000MHz and the memory at 1400MHz. From there we increased the voltage to increase stability, but the only time we really ran into an issue with the stock voltage was at 1100MHz. The issue wasn't that the cards would crash the system at this point, but rather that the benchmarks would actually freeze for a few seconds before continuing on. In order prevent this from happening, we had to increase the core voltage to 1206mV, and from that point on all the graphics cards ran like a dream at 1100MHz core and 1575MHz memory (6300MHz QDR).

At these clock speeds, the HD 7950 graphics cards not only have substantially more processing power, but their memory bandwidth is also increased. In total, these clocks represented an increase of 18.2% for the XFX and Sapphire models and 25% for the PowerColor model, with the difference due to the higher clock speeds of both the Sapphire and XFX graphics cards. In our opinion, there is plenty of additional headroom left on these cards for anyone brave enough to unlock the frequency cap.

Hardware Configuration:

Drivers:

Benchmarks DX11:

Test Settings:

Usage:

Specifications:

(Note: All models might not be included in this review. The table below is to be used for comparison purposes)
AMD Specifications
Model
AMD Radeon HD 7970 AMD Radeon HD 7950
AMD Radeon HD 5870 AMD Radeon HD 6950 AMD Radeon HD 6970
Processing Cores
2048 1792 1600 1408 1536
Core Clock
925MHz 880MHz / 900MHz
850MHz 800MHz 880MHz
Memory Clock
1375MHz 1250MHz 1200MHz 1250MHz 1375MHz
Memory Interface
384-bit 384-bit 256-bit 256-bit 256-bit
Memory Type
3GB GDDR5 3GB GDDR5 1GB GDDR5 2GB GDDR5 2GB GDDR5
Fabrication Process
28nm 28nm 40nm 40nm 40nm
NVIDIA Specifications
Model
Nvidia GTX 460 Nvidia GTX 470 Nvidia GTX 480 Nvidia GTX 570 Nvidia GTX 580
Processing Cores
336 448 480 480 512
Core Clock
675MHz 607MHz 700MHz 742MHz 782MHz
Memory Clock
1100MHz 837MHz 924MHz 1250MHz 1002MHz
Memory Interface
256-bit 128-bit 320-bit 320-bit 384-bit
Memory Type
1GB GDDR5 1.25GB GDDR5 1.5GB GDDR5 1.25GB GDDR5 1.5GB GDDR5
Fabrication Process
40nm 40nm 40nm 40nm 40nm

Futuremark's latest 3DMark 2011 is designed for testing DirectX 11 hardware running on Windows 7 and Windows Vista. The benchmark includes six all new benchmark tests that make extensive use of all the new DirectX 11 features including tessellation, compute shaders and multi-threading.

Out of the gate we can see the additional 20MHz give the XFX and Sapphire models a little more kick, but as the presets were increased the gap between the cards narrowed. Once we overclocked the HD 7950 to 1100MHz/1575MHz it was a pixel pushing machine, as it managed to outperform even the HD 7970.

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

Again all of the graphics cards featured in the review performed at the same level, but in this benchmark the differences between the 880MHz core and 900MHz core didn't really yield much in the way of additional performance.

Aliens vs Predator 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.

At their respective clock speeds, the three models we tested were second to only the Radeon HD 7970 itself.

Batman: Arkham City is the sequel to the smash hit, Batman: Arkham Asylum. The game was created with the Unreal 3 Engine, and includes areas with extreme tessellation, high res textures and dynamic lighting. Batman, also includes native support for PhysX and is also optimized for Nvidia 3DVision technology.

Just like the previous benchmark, the three HD 7950 graphics cards each showed excellent performance, outperforming the reference GeForce GTX 580. We are also continuously impressed with the overclocking results, because once the Tahiti Pro GPU is clocked up to 1100MHz it just produces excellent results across the board.

Battlefield 3 is designed to deliver unmatched visual quality by including large scale environments, massive destruction, dynamic shadows. Additionally, BF 3 also includes character animation via ANT technology, which is also being utilized in the EA Sports franchise. All of this is definitely going to push any system its threshold, and is the reason so many gamers around the world are currently asking if their current system is up to the task.

Unlike the other games we benchmark, the performance of Battlefield 3 is tested during online game play. We ensure our results are accurate by running through each resolution four times before averaging the results.

The three custom models continue to show excellent scaling across the benchmarks. In Battlefield 3, the Sapphire, PowerColor and XFX models were all able to achieve higher frame rates than the GTX 580, and once overclocked they were the fastest graphics cards in our testbed.

Crysis 2 is a first-person shooter developed by Crytek and is built on the CryEngine 3 engine. While the game was lacking in graphical fidelity upon its release, Crytek has since added feature such as D11 and high quality textures. This improved the in-game visuals substantially, which in turn pushes even high-end hardware to the max.

So far Crysis 2 is the only benchmark where the HD 7950s were not able to outperform the GTX 580. However, the difference is small and AMD has not yet optimized the drivers for this specific title.

DiRT 3 is the third installment in the DiRT series and like it's predecessor incorporates DX11 features such as tessellation, accelerated high definition ambient occlusion and Full Floating point high dynamic range lighting. This makes it a perfect game to test the latest DX11 hardware.

DiRT 3 puts the cards back on track prior to their hiccup in Crysis 2. In this benchmark, the three tested HD 7950 graphics cards were slightly faster than the GTX 580 and significantly faster than all the other single GPU graphics cards.

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 perform under the latest standard.

The results in Metro 2033 were the best we have seen from the cards thus far, as the gap between the GTX 580 and HD 7950 offerings was substantial. However, the difference is mainly due to the larger memory buffer of the HD 7950, so games that are able to utilize all the available memory bandwidth will perform better on Southern Islands graphics cards.

Total War: Shogun 2 is a game that creates a unique gameplay experience by combining both real-time and turn-based strategy. The game is set in 16th-century feudal Japan and gives the player control of a warlord battling various rival factions. Total War: Shogun 2 is the first in the series to feature DX11 technologies to enhance the look of the game, but with massive on-screen battles it can stress even the highest-end graphics cards.

Total War is the sixth out of seven benchmarks where a slight bump in the GPU clocks speed help produce results better than the GTX 580, which currently has a similar MSRP. Just like all the benchmarks before this, overclocking leads to excellent scaling, and time after time the cards were able to render more pixels per second than the stock HD 7970.

Temperature:

To measure core GPU temperatures, we run three in-game benchmarks and record the idle and load temperature according to the min and max temperature readings recorded by MSI Afterburner. The games we test are Crysis 2, Lost Planet 2 and Metro 2033. We run these benchmarks for 15 minutes each. This way we can give the included thermal solution and GPU time to reach equilibrium.

Between the three graphics cards the PowerColor model had the lowest temps, followed by the Sapphire model and then XFX R950.

Looking at them compared to the reference version we can see that they are all more efficient, even with the higher clock speeds and all three cards were extremely quiet as well. When measuring the noise output all the graphics cards had a decibel range between 47 and 49dBA, which is where the case fans we use measure as well. This simply means all three of the graphics cards were quieter than the fans installed inside our Corsair 600T chassis. There were a few times when the cards would peek above 52dBA, but it was always short lived, as the fans would throttle down fast.

Power Consumption:

To measure power usage, a Kill A Watt P4400 power meter was used. Note that the 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 after running the system through the same in-game benchmarks we used for the temperature testing. This way we are recording real-world power usage, as opposed to pushing a product to it's thermal threshold.

The order in which the three cards compared in our power consumption testing was exactly the same was what we saw in the temperature test. This gives the PowerColor model a slight edge, with the Sapphire card in the middle and XFX card in third. Of course this is due to the varying clock frequencies and voltage, which the PowerColor model at 880MHz is going to be the lowest.

Between the tw 900MHz cards the difference was within just a few watts, so both are efficient, but the Sapphire model does appear to draw less voltage at 900MHz than the XFX model.

The first graphics card I dropped five bills on was an NVIDIA 5950 Ultra, and it is remarkable how far the graphics market has come since that time. Custom designs are now light years ahead of where they used to be, and the three models we looked at in this review are a shining example of this. All three of the graphics cards we examined, regardless of the company, displayed excellent performance, thermal efficiency, overclocking headroom and acoustics. So, all three companies really hit the nail on the head and produced outstanding graphics cards that offer a better out-of-the-box experience in comparison to the reference HD 7950 models.

Out of the three graphics cards, the XFX and Sapphire models were slightly faster out-of-the-box due to the 900Mhz clock speed. However, the PowerColor model only lagged by a few frames-per-second and in some benchmarks the additional 20MHz didn’t translate into any appreciate differences between the higher clocked models. Additionally, all three graphics cards easily overclocked their GPU engine and memory clock to 1100MHz and 1575MHz (6300MHz effective). At this level, all the graphics cards displayed exceptional performance, easily pushing them ahead of both the stock GTX 580 and HD 7970. With the improved thermal solutions, all three of the graphics cards managed to keep the core cool, even when we were pumping up to 1206mV into the core.

Since these models are all overclocked and come with souped-up thermal solutions, they command a slightly higher MSRP. At time of launch the Powercolor PCS+ HD 7950, Sapphire HD 7950 OC and XFX R7950 BE will be priced at $469, $479 and $499, respectively. This makes them between $30 and $50 more expensive than the stock models. However, a quick look over at Newegg shows all three currently priced at $499, still these SKUs are quieter, more efficient and possibly overclock higher than the reference models. So, overall all three of these graphics cards are a good buy, if you have the scratch. If not, the best bet is to wait for the prices to drop in the following months when NVIDIA releases the Kepler series.

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