AMD Radeon HD 7870 & HD 7850 Review

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Deus Ex: Human Revolution (DX11)

Deus Ex: Human Revolution (DX11)

Deus Ex: Human Revolution may not be the hardest game for today’s high end gaming rigs to render. While the game mostly takes place indoors, it is the few outdoor areas that put additional strain on graphics cards. So for this test, we use one of the more involved outdoor sections: the Sharif Manufacturing Loading Docks.

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Dirt 3 (DX11)

Dirt 3 (DX11)

Dirt 3 isn’t all that much different from its predecessor but the developers have added a few more visual touches but boost image quality. In this case, we used the Michigan Rally track since it features some of the hardest to render features of the game: expansive vistas, water, dirt effects, trees and many other items.

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Metro 2033 (DX11)

Metro 2033 (DX11)

For this test we use a walkthrough and combat scene from The Bridge level which starts at the beginning of the level and lasts for about 3 minutes of walking, running and combat. Famerates are measured with FRAPS and Advanced PhysX is turned off.

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Shogun 2: Total War (DX11)

Shogun 2: Total War (DX11)

Due to its very nature, Shogun 2 is a tough game to benchamark since the in-game tool doesn’t accurately convey an in-game experience. So we took a pre-recorded battle which pits three large armies against one another and includes camera zooms, fog, gun smoke and other items. Using a pre-recorded sequence also effectively removes the CPU from the equation since it doesn’t have to process AI.

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The Witcher 2 (DX9)

The Witcher 2 (DX9)

The Witcher 2 may be a DX9 based game but its graphics quality is beyond reproach. In this benchmark we take an area out of The Kayran mission and include one of the toughest effects the graphics engine has in store for the GPU: rain. Throughout this sequence, rain plays a large part but explosions, combat and even some sun shafts are included as well.

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Temperatures & Acoustics / Power Consumption

Temperature Analysis

For all temperature testing, the cards were placed on an open test bench with a single 120mm 1200RPM fan placed ~8” away from the heatsink. The ambient temperature was kept at a constant 22°C (+/- 0.5°C). If the ambient temperatures rose above 23°C at any time throughout the test, all benchmarking was stopped. For this test we use the 3DMark Batch Size test at its highest triangle count with 4xAA and 16xAF enabled and looped it for one hour to determine the peak load temperature as measured by GPU-Z.

For Idle tests, we let the system idle at the Windows 7 desktop for 15 minutes and recorded the peak temperature.

The temperature results above don’t actually mean all that much due to a number of factors. Neither of these cards’ reference coolers will be featured on many retail boards since AMD’s partners have largely decided to eschew them in favor of custom setups. In addition, the HD 7850 we received will never be available with our sample’s heatsink design. With that being said, the results were very, very good in both cases.

Acoustical Testing

What you see below are the baseline idle dB(A) results attained for a relatively quiet open-case system (specs are in the Methodology section) sans GPU along with the attained results for each individual card in idle and load scenarios. The meter we use has been calibrated and is placed at seated ear-level exactly 12” away from the GPU’s fan. For the load scenarios, a loop of Unigine Heave 2.5 is used in order to generate a constant load on the GPU(s) over the course of 20 minutes.

Once again, due to the fact that neither card will be widely available with the fans our samples came with, there really is much point in paying all that much attention to these results. We can however infer one thing from the low noise profiles of both cards: the Pitcairn core doesn’t produce all that much heat when operating at reference speeds so even a basic heatsink setup should be more than capable of handling it without resorting to loud high RPM fans.

System Power Consumption

For this test we hooked up our power supply to a UPM power meter that will log the power consumption of the whole system twice every second. In order to stress the GPU as much as possible we once again use the Batch Render test in 3DMark06 and let it run for 30 minutes to determine the peak power consumption while letting the card sit at a stable Windows desktop for 30 minutes to determine the peak idle power consumption. We have also included several other tests as well.

Please note that after extensive testing, we have found that simply plugging in a power meter to a wall outlet or UPS will NOT give you accurate power consumption numbers due to slight changes in the input voltage. Thus we use a Tripp-Lite 1800W line conditioner between the 120V outlet and the power meter.

As with every one of the other HD 7000-series cards, the HD 7870 and HD 7850 set new benchmarks in the field of GPU efficiency. It really is amazing to see what AMD has been able to accomplish with the 28nm manufacturing process and hopefully this trend continues as new cards are released.

 

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Overclocking Results

Overclocking Results

Overclocking has quickly become a standard practice for anyone that owns an HD 7000-series GPU for a number of reasons. First and foremost among these is the willingness of the cards to reach high frequencies with very little effort and the resulting performance increase can vault even a lowly HD 7770 into a whole new market segment.

To attain the results below, we overclocked using AMD’s Overdrive utility with the default fan speed profile enabled and the PowerTune limit set to +20. Voltages were kept to their reference levels as well. Also take note that if an overclock could not complete our entire test suite (benchmark sequences of every game listed in this review, at every resolution) equaling roughly 2 hours of game time, it was not included in the results below. As such, we are confident that our final clock speeds are entirely stable for gaming purposes.


HD 7870 Results

AMD’s Catalyst Control Center includes some generous core and memory limits for the HD 7870 but without any voltage adjustments, we weren’t able to max either of them. Nonetheless, it hit a core speed of 1196MHz while the memory hit a blistering speed of 5204MHz before the GDDR5’s error correction routines began throttling performance. All in all this is an excellent result and as you will see below, in game performance really was something to behold for a $349 card.


HD 7850 Results

AMD has instituted some strict limits for how far the HD 7850’s core can overclock but once again we weren’t able to attain anything close to 1050MHz. Instead, our card topped out at 1002MHz but the memory fared much better with a top speed of 5228MHz, one upping the HD 7870’s overclock by a few points.

 

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HD 7870 GHz Edition; Conclusion

HD 7870 GHz Edition Conclusion

As evidenced throughout this review, there is are plenty of choices between the $200 and $350 price points yet AMD has successfully navigated around the pitfalls that normally arise when parachuting a card into such a competitive market. Their HD 7870 when up against some longstanding heavyweights and it usually came out on top.

The 28nm manufacturing process is paying dividends for AMD by keeping power consumption abnormally low –we’re talking HD 6850 levels here- while clock speeds are tickling the 1GHz mark. This has allowed the HD 7870 to not only compete with some of the previous generation’s enthusiast level products but it has also granted a fair amount of overclocking headroom. Our sample almost hit the 1.2GHz mark, granting performance that was equal to that of a HD 7950 and we’re guessing that with a bit more juice higher levels would have been easily achievable.

Overclocking headroom and lower power consumption may look great on paper but the HD 7870 doesn’t come cheap. A price of $349 puts it firmly into the upper midrange which could have caused some serious problems considering this is the current domain of NVIDIA’s GTX 570 and AMD’s now EOL’d HD 6970 2GB. Instead of falling flat, the HD 7870 2GB rose to the occasion by handily beating the HD 6950 and in most cases pulling well ahead of the aforementioned HD 6970. Granted, the price / performance goal posts haven’t been moved all that much against fellow AMD cards but unlike the HD 7770, we’re seeing some meaningful steps in the right direction.

The HD 7870 is particularly successful since it offers most of the HD 7950’s performance at a fraction of its cost, provided resolutions stay at 1920 x 1200 or less. This does however cause some tension within AMD’s own lineup. With such a minimal performance difference at today’s most popular resolutions and a large $100 price difference between the two, AMD may have effectively castrated the HD 7950’s chance of market success. That’s great news for anyone looking to drop $350 on a graphics card but early adopters who bought a HD 7950 can’t be feeling all that happy right now.

When compared against NVIDIA cards, the HD 7870 is able to achieve some impressive results but once again we’re not seeing all that much progression from one generation to the next. It may narrowly beat a GTX 570 but let’s not forget that card was launched at an identical $349 price more than a year ago. However, the HD 7870’s 15% average improvement at high resolutions is particularly important since this speaks to a level of high image quality performance that will be necessary for upcoming games. More importantly, performance comes dangerously close to equaling the GTX 580 and if it wasn’t for NVIDIA’s latest drivers being released a few weeks ago, these numbers would have been even closer.

If you are in the market for a sub-$400 GPU or are looking to step up from a HD 5800-series product, the HD 7870 2GB is the card you'll want to pick up. It has all the makings of a success story: great performance, a relatively affordable price, low power consumption, quiet operation and plenty of overclocking headroom. With that being said, AMD may become a victim of their own success since they’ve almost made it impossible to recommend the $450 HD 7950 3GB unless there's an absolute need for the extra memory bandwidth it brings to the table.

 

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HD 7850 2GB; Conclusion

HD 7850 2GB Conclusion

The HD 7850 doesn’t quite live up to the performance levels of its sibling but most of our praise for the HD 7870 applies here as well. While it may not be able to achieve the framerates necessary to be considered a high end solution, the Pitcairn Pro’s goals are grounded firmly within market realities, making this solution not only affordable but infinitely more appealing to the gaming masses. By hitting the $249 mark, AMD has put this card up against some of the most popular GPUs from the last two years and for the most part, it is able to compete quite well.

One of the main advantages of the HD 7850 is AMD’s move to a 2GB, 256-bit memory interface. At first glance this may not be of much interest to mainstream gamers playing on lower resolution monitors but the landscape is quickly moving on. These days, most entry level panels are available in 1080P form and this is changing the metrics for what it takes to provide decent framerates, particularly as games begin featuring increased texture sizes, more geometry and exotic forms of anti aliasing.

We can see examples of how bandwidth and architectural differences can affect performance by looking at the HD 7850’s performance against two 1GB cards: the GTX 560 Ti and HD 6870. In both cases the cards run relatively close to one another at 1920 x 1200 but as image quality settings increase, the HD 7850’s lead grows by leaps and bounds. Even the GTX 560 Ti 448 sees its leads all but erode once higher resolutions are reached and make no mistake about it; the HD 7850 is still able to perform well at 2560 x 1600 if given the chance.

As with the HD 7870, we couldn’t have asked for more in terms of efficiency and overclocking capabilities. The sought after 1GHz mark was attainable even without voltage tuning and while your experience may differ, this resulted in unheard of performance levels for a $250 card. Meanwhile, power consumption was by far the best we’ve seen from a GPU that can play games at high settings.

Our one critique about many of AMD’s newest cards unfortunately remains true to form once again. While the move towards 2GB is a welcome addition, the HD 7850 is in no way a game changing card. It won’t provide any improvement if you already bought into the GF114 or Cayman Pro architectures and in some cases the $190 GTX 560 Ti can still be considered a better purchase for today’s applications. However, for anyone still using an HD 6870, GTX 460 or HD 5850 it provides a nearly perfect upgrade path, especially when the needs of upcoming games are taken into account. In today’s market, that makes the HD 7850 2GB a great buy for anyone that wants peace of mind for the next few years.