PowerColor HD 7850 PCS+ Review

Author: Chris Ledenican
Editor: Howard Ha
Publish Date: Wednesday, May 23rd, 2012
Originally Published on Neoseeker (http://www.neoseeker.com)
Article Link: http://www.neoseeker.com/Articles/Hardware/Reviews/PowerColor_HD_7850_PCS/
Copyright Neo Era Media, Inc. - please do not redistribute or use for commercial purposes.

After the launch of the Kepler series, NVIDIA has essentially locked in the high-end market. Yet without a mid-range Kepler product, the AMD Radeon HD 7870 and HD 7850 still reign supreme in their respective price segments. This is due to Pitcairn based graphics cards having the same performance as last generation’s high-end boards, all while consuming less energy and creating less noise. The Pitcairn graphics we are going to be examining today comes to us from PowerColor, but seeing as it is part of the PCS family, it sports more efficient design and higher clocks speeds.

As part of AMD's Southern Islands architecture family, the PowerColor HD 7850 PCS+ comes with all the latest technologies such as Eyefinity 2.0, AMD HD3D technology, and Accelerated Parallel Processing. PowerColor has enhanced the reference board design by including their Gold Power Kit design along with a DrMos Digital PWM, multi-phase design and a large direct contact heatsink. Additionally, the PowerColor HD 7850 PCS+ has higher clock speeds than the reference boards. Out of the box, the PCS+ card has a GPU clock speed of 1000MHz, up from 860MHz, and a memory clock of 1225MHz.

Even with higher clock speeds, improved power circuitry and a robust thermal solution, the PowerColor PCS+ is priced only $10 higher than the reference models.

Specifications
Graphics Engine
Radeon HD 7850
Video Memory
2GB GDDR5
Engine Clock 1000MHz
Memory Clock 1225MHz x 4 (4.9Gbps)
Memory Interface 256bit
DirectX Support
11.1
Standard Display Connectors
DL-DVI-I/ SL-DVI-D / HDMI / MINI DPx2
Bus Standard
PCIE 3.0

The PowerColor PCS+ comes packaged in a sleek box that lists all the key features of the graphics card on the front along with an image of a powerful sports car burning up the road. This is supposed to give you a sense of this model being faster than the reference design, a theme further reinforced by four icons found just under the car. These icons highlight how this model is 15% more stable, cooler and quieter than the reference design, as well as being faster at stock and having exceptional overclocking potential.

Since the PowerColor HD 7850 PCS+ uses the Pitcairn Pro graphics processor, the GPU is stocked with 16 Compute Units to give it 1024 streaming processors, 8 Render Back-Ends, 512KBs of read/write L2 cache, and a 256-bit memory bus that all runs on a PCI Express 3.0 x16 interface. In addition, the GPU is built on a 28nm node and has a total of 1.5 billion transistors. The GPU also includes a single geometry engine that has its own Rasterizer and Render Back-End unit, but shares the 16 Compute Units.

Where the PowerColor model differs however is its base clocks; at 1000MHz, the GPU clock has been increased by over 16% over the reference design. This should give this model a decent boost when it comes to pushing pixels, as PowerColor didn't opt for the standard 5% overclock. The 2GB GDDR5 memory also comes overclocked at 1225MHz, but this increase is not as dramatic as the GPU factory overclock.

From an aesthetic standpoint, the PowerColor HD 7850 PCS+ is a rather slick card. At the top of the card is a large heatsink cover that is predominately black, but has a white back end with the PCS logo. The white adds a nice contrast to the card, but what really stands out is the massive, centrally mounted 90mm fan. The surface of the heatsink cover uses what is best described as a soft plastic, making the card feel smooth to the touch, and fingerprint resistant.

Since the PowerColor HD 7850 PCS+ has the same feature-set as other cards in the Southern Island family it comes equipped with PowerTune technology. By now most of us are familiar with this technology, but as a quick recap, PowerTune is basically a power management system that maximizes the performance of the board via dynamic power adjustment. It does this by increasing the GPU clock speed in real time when the GPU detects power headroom, and throttling the clocks when a certain power limit is exceeded. This allows the board to adjust the clock speeds on a microsecond level.

PowerTune eliminates the TDP rating and instead lists the power under average use. According to these ratings the HD 7850 has a PowerTune rating of 130W, but since the PCS+ is an overclocked model it is going to use more power. Still, even with the higher power rating the board only requires a single 6-pin power connector which is found at the back-end of the PCB.

Since the release of Southern Islands we have been seeing a growing trend where graphics card manufacturers are dialing back the video outputs to last generation's designs. In the case of the PowerColor model, the reason to do this is twofold. For starters, since the thermal solution is more efficient than the reference models there is no need for a high airflow bracket. Secondly, with two DVI ports it is actually easy to setup Eyefinity out of the box.

With this modified design the PowerColor PCS+ has dual Mini-DP connectors, a single HDMI 1.4a connector and two DVI connectors. The Mini-DP ports use the new 1.2 standard which allows them to support up to three monitors per connection, and also includes support for AMD's HD3D technology. There are also two DVI ports on the HD 6850, which due to bandwidth limitations use a different connection standard. Of the two, the topmost is a DL-DVI port which supports 30" monitors with resolutions up to 2560x1600, while the other DVI port uses the single-link connection type that supports resolutions up to 1920x1200.

The on-board DisplayPort uses the 1.2 standard, enabling support for up to three monitors per port (via MST Hub), as well as 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 teamed together to support HD3D Surround, which is a feature new to Eyefinity 2.0.

The top portion of the thermal solution consists of a centrally mounted 90mm fan that is positioned in the middle of the shroud. With such a large fan, the airflow area is maximized to extend across the entire heatsink below, which increases the exhaust rate of any heat built up in the thermal solution. The size of the fan also allows it to operate at a lower RPM level which reduces the acoustics. There is also an on-board 4-pin PWM fan controller that dynamically adjusts the fans RPM level for the best thermal and acoustic results.

Beneath the heatsink enclosure is a large direct contact heatsink. There is a large fin-stack up at the top that extends across the length of the PCB. The fin-stack is then connected to the base of the cooler via two heatpipes that zigzag though it, the middle, and both opposite ends. By extending the heatpipes though three separate areas of the fin-stack, the heat is more efficiently spread throughout the area instead of it all being built up in one spot.

The base of the heatsink has dual heatpipes running through it. Each heat pipe has been filed down to copper and smoothed level. This design eschews the standard cooling plate and instead relies on the heatpipes themselves to directly absorb the heat from the core by cutting out the middleman, which in this case would be a standard base.

The PowerColor PCS+ HD7850 utilizes a Gold Power Kit design with DrMos, Digital PWM and Multi-phase technology to increase both the stability and overclocking potential. The design improves the stability by up to 15% in comparison to the reference model. In addition, the PowerColor PCS+ has 8 memory chips manufactured by HYNIX that are each 256MB, for a total of 2GB on the card.

Overclocking:

Overclocking the Sapphire HD 7850 PCS+ was extremely easy, but without voltage control we could only get it to 1050MHz. By default this model has a base clock speed of 1000MHz, which is already 140MHz beyond the reference design, and our past testing of this GPU saw it cap out at right around 1050MHz. For this reason we were not surprised by our results. The memory however did relatively well by comparison. In our system we were able to increase the GDDR5 memory from 1225MHz to 1450MHz. That's an increase of 18.4%, which is good considering it already has a high clock frequency.

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 comparisons)
AMD Specifications
Model
AMD Radeon HD 7970 AMD Radeon HD 7950 AMD Radeon HD 7870 GHz Edition PoweColor HD 7850 PCS+
AMD Radeon HD 6970
Processing Cores
2048 1792 1280 1024 1536
Core Clock
925MHz 850MHz 1000MHz 1000MHz 880MHz
Memory Clock
1375MHz 1250MHz 1200MHz 1225MHz 1375MHz
Memory Interface
384-bit 384-bit 256-bit 256-bit 256-bit
Memory Type
3GB GDDR5 3GB GDDR5 2GB GDDR5 2GB GDDR5 2GB GDDR5
Fabrication Process
28nm 28nm 28nm 28nm 40nm
MSRP
$479 $379 $329 $259 $349
NVIDIA Specifications
Model
Nvidia GTX 670 Nvidia GTX 680 Nvidia GTX 480 Nvidia GTX 570 Nvidia GTX 580
Processing Cores
1344 1536 480 480 512
Core Clock/ Boost Clock
915MHz / 980MHz 1006MHz / 1058MHz 700MHz 742MHz 782MHz
Memory Clock
1504MHz 1504MHz 924MHz 1250MHz 1002MHz
Memory Interface
256-bit 256-bit 320-bit 320-bit 384-bit
Memory Type
4GB GDDR5 2GB GDDR5 1.5GB GDDR5 1.25GB GDDR5 1.5GB GDDR5
Fabrication Process
28nm 28nm 40nm 40nm 40nm
MSRP
$399 $499 $239 $299 $389

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.

The increased clock speeds really helped take performance to the next level In 3DMark 11. Compared to the reference model, the PCS+ scored 17.9% higher in the Entry benchmark, 16% higher in Performance, and 15% higher at the Extreme settings.

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.

The performance difference in Unigine was not in the double digit range as it was in 3DMark 11, but the PowerColor model was still 9% faster at the default settings, and 15% faster once overclocked.

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.

The Top graph reflects our results at 1920x1080, while the lower graph reflects our results Eyefinity and Surround results at 5760x1080.

The results in Batman proved too dramatic to simply attritube to the default 1000MHz clock speed, especially when you notice how much better it performed even in comparison to the HD 7870. Our best guess is this could be related to an game update, but further testing will be needed before we can draw a final conclusion.

The results during the Eyefintiy portion of the testing were more in line with what we expected to see, as the HD 7850 PCS+ was 3FPS faster at 5760x1080 than the reference model.

Battlefield 3 is designed to deliver unmatched visual quality by including large scale environments, massive destruction and 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.

The Top graph reflects our results at 1920x1080, while the lower graph reflects our results Eyefinity and Surround results at 5760x1080.

Battlefield 3 is an extremely demanding game, so it isn't surprising to see the PCS+ model end up only 3FPS faster than the reference board. This is still a net gain of 7%, which put us well beyond the 30FPS minimum.

The PowerColor struggled at 5760x1080, and was not able to reach a smooth frame rate with our benchmark settings.

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.

The Top graph reflects our results at 1920x1080, while the lower graph reflects our results Eyefinity and Surround results at 5760x1080.

In Crysis 2 the PowerColor PCS+ was 11% faster than the base model and only 4% slower than the HD 7870. Once overclocked, it managed to best the 7870 by a whole 1FPS.

Once again we are seeing how these cards are not particularity strong at 5760x1080. However, if the settings were reduced to medium levels we still feel they have the power to run most DX11 games above 30FPS.

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.

The Top graph reflects our results at 1920x1080, while the lower graph reflects our results Eyefinity and Surround results at 5760x1080.

The PowerColor card had no issues running DiRT 3 at 1080p, nearing the holy grail of 60FPS, and was 13.7% faster than the reference model.

At 5760x1600 the HD 7850 continues to struggle to achieves 30FPS, but at least in this benchmark it came close.

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 Top graph reflects our results at 1920x1080, while the lower graph reflects our results Eyefinity and Surround results at 5760x1080.

Metro 2033 traditionally performs better on AMD graphics cards, so the results here should not be surprising to anyone. In this benchmark the PowerColor PCS+ was dead even with the NVIDIA GTX 580 and 12% faster than the reference model.

The results at 5760x1080 were actually surprising this time around, as the PowerColor PCS+ was extremely close to hitting 30FPS once overclocked.

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.

We round things out with the PowerColor PCS+ being 10% faster than the base model in Shogun 2, and about even with the GTX 570. In the majority of our benchmarks, the PowerColor model was either 10% faster (or higher) than the cards using the default 860MHz clock. That's actually quite good for a factory overclocked graphics card.

Unfortunately the higher clock speeds are once again not enough for the HD 7850 to be able to game at 5760x1080, so if you are planning on gaming above 1080p, a stronger graphics card would be recommended.

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.

The maximum temperature of the PowerColor model was slightly higher than the reference design, but this card ran virtually silent while the reference model is known for being quite loud at times.

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.

Since the PowerColor PCS+ is an overclocked model it does require slightly more power to run at the target clock speeds. However, the difference is only around 4 percent, well under the 10 to 13 percent increase in performance.

By design the PowerColor HD 7850 PCS+ is built to deliver better thermal performance, stability and lower acoustic levels. All of these make it superior to the reference models, but with a default clock speed of 1000MHz it is also much faster than the cards using the standard 860MHz clock. In our testing this led to the PowerColor model being around 10% to 13% faster than the reference model on average. This is actually a decent increase in performance, considering most overclocked graphics cards have only a 5% boost which translates to a marginal increase in performance. In addition, this card is built around high-quality components so even with the higher clock speeds, the risk of the power circuitry failing is reduced.

Along with the increased performance the PowerColor HD 7850 PCS+ also includes an exceptional thermal solution. In our testing the Pitcairn Pro GPU never exceeded 68°C even during the most demanding benchmark. However, it did run slightly hotter than the reference model. The reason for this is the reference card we were sent used the larger heatsink designed for the HD 7870 with a blower style fan. This makes it hard to make a direct comparison, but the PowerColor design was close in terms of performance. When it came to noise levels though, the PowerColor model was in another class altogether. In fact, there was hardly a time when we heard the fan over the case fans installed in our Corsair 600T.

The only downside is there is very little headroom left for overclocking. This being the case, it would have been nice to see a voltage control option that allowed us to free up more juice for the core. This would result in a higher overclocking ceiling and since the thermal solution was more than adequate for the job, we wouldn't be surprised if the core could hit 1100MHz with additional power. Still, most HD 7850 graphics cards do max out at 1050MHz, so this is not an issue specific to this model.

For all that this card offers, it is surprising PowerColor is only charging $10 over cards using the reference design. This makes the final MSRP around $259, which in our opinion is a steal.

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