Monday, November 29, 2010

Roundup: Four Radeon HD 6850 1 GB Cards Compared

Improvements to performance, acoustics, and bundles can add big value once a reference graphics card is modified by third-party vendors. We compare four modified Radeon HD 6850 1 GB boards to find out which company's additions best suit your gaming needs.
Some say green is the new red, and no place is that more true than in the rebranding of ATI to AMD. And yet, marketing similarities between AMD and Nvidia don’t end in color, as the newer, more efficient Radeon HD 6850 offers performance and a price nearly identical to Nvidia's GeForce GTX 460 1 GB. If you want to know more about the card itself, check out our launch review of the Radeon HD 6870 and 6850.
AMD’s slightly better power consumption figures mean that buyers of the new green team can go green for the same green, while saving a little green over the life of the card (Ed.: Xzibit approves, dawg).

If you believe this makes the Radeon HD 6850 a perfect mid-priced performance part, you're in good company, as the number of folks willing to spend ~$200 is much greater than the market for flagship $500 boards.
If you're ready to buy, there are plenty of options available. Some vendors even offer multiple models. Choosing a card certainly doesn’t have to be difficult. We simply asked every major manufacturer to send its best, and those who didn’t have anything to offer beyond AMD's reference design chose not to participate. That left us with four souped-up models for your consideration.

Radeon HD 6850 1 GB Comparison Specifications
Asus EAH6850
MSI R6850
PowerColor AX6850
Sapphire Toxic 6850
GPU Clock790 MHz775 MHz820 MHz820 MHz
DRAM RateGDDR5-4000GDDR5-4000GDDR5-4400GDDR5-4400
DVITwo Dual-LinkTwo Dual-LinkTwo Dual-LinkTwo Dual-Link
DisplayPortFull-SizeFull-SizeFull-SizeDual Mini
VGABy Adapter (x1)By Adapter (x1)By Adapter (x1)By Adapter (x1)
Mini to Full DP
Weight18 Ounces16 Ounces19 Ounces27 Ounces
PCB VersionC223 Rev. 1.00V224 V1.0LF R97FF V1.0109-C22237-00
VRMThree PhasesThree PhasesFour PhasesFour Phases
WarrantyThree YearsThree YearsTwo YearsTwo Years
Added ValuePCIe Power Adapter
CrossFire Bridge
CD Wallet
PCIe Power Adapter
CrossFire Bridge
CrossFire Bridge
Free "Call of Duty:
Modern Warfare 2"
6' HDMI Cable
2 x PCIe Power Adapter
CrossFire Bridge
Price$200 $205 $210 $210 

Also known as model EAH6850 DC/2DIS/1GD5, Asus’ barely-overclocked Radeon HD 6850 includes enhanced cooling and advanced voltage control to let buyers decide the best performance-to-noise ratio.

A custom 9.7” circuit board faces its single six-pin PCIe power connector, easing installation into shorter cases. The DirectCU heat pipes add around 3/8” to the cooler’s height without affecting power connector placement, while a steel rail on the card’s top edge braces it against the extra weight of that cooler.

Placement into narrow cases or certain space-saving cube designs could potentially be problematic, but Asus’ design makes sense for the majority of performance PC builders.

Clocked only 15 MHz higher than AMD’s reference GPU specification and with no bump in memory frequency, the EAH6850 DC/2DIS/1GD5 offers builders a core voltage range of 0.95 to 1.35 V to do their own custom tuning.

Asus SmartDoctor provides the EAH6850 DC/2DIS/1GD5 slide controls for voltage, GPU, and DRAM frequencies from its main menu. Users can select GPU frequencies between 600 and 1000 MHz, DRAM data rates between 3000 and 5000 MT/s, and core voltage from 0.95 to 1.35 V.

Advanced menus control overheat protection, alarm settings, and startup options.

A third advanced menu allows fan speed to be set at four thermal presets. Lower temperatures can help overclockers achieve higher settings.

SmartDoctor’s HyperDrive menu allows users to set an active GPU clock boost, activated when a 3D game is detected.

A quick look at the package reveals that our test unit is the OC Edition of MSI’s R6850 PM2D1GD5, separated from MSI’s reference-speed R6850 PM2D1GD5 only by clock rate.

The difficulties we had trying to set this article up at the end of October are bluntly revealed in this board. The OC Edition was initially listed on MSI’s Web site, only to disappear later. AMD’s Radeon HD 6850 graphics processor has little room to overclock at or near stock core voltage, and MSI cancelled its OC Edition card rather than risk instability.

Several factors caused us to keep MSI in the running for this roundup. First is that all our reference-clocked cards are dispersed across other test labs around the country, and including one as a reference point in this story is a useful way to show how much better overclocked samples perform.
Second is that the OC Edition card uses the same hardware as MSI’s standard-edition R6850 PM2D1GD5, so that underclocking allows the faster card to represent the performance level of its reference-clocked sibling.

The R6850 PM2D1GD5 uses the same 8.5”-long circuit board design as the HIS model from our launch article, with three of its four voltage regulators enabled. While the cooler extends the card’s overall length, the 8.6” distance from the card’s face to the end of its PCIe power connector will be more important to those who plan to use a small case.

The current version of MSI Afterburner did not support voltage changes on this particular card as of this writing, though MSI has fixed this missing option in past cards through Afterburner updates. Other functions already work perfectly, including core clock, memory clock, fan speed, and advanced controls.

While manual changes stick between reboots, advanced fan maps require the software to be running. We believe MSI’s fan mapping is the best in the industry, and startup options allow it to launch automatically and be minimized to the task bar.

Monitoring, logging, and OSD options take up two more pages of the advanced menu.

MSI adds a screen capture function that automatically saves a game image.

Up to four overclocked configurations can be saved as profiles, with launch options that include game-based performance increases.

One of the two highest-clocked samples in today’s roundup, PowerColor’s PCS+ AX6850 sweetens the deal with a free download of Call of Duty: Modern Warfare 2.

That “deal” is for a card that includes a four-phase voltage regulator to stably support its high clock rates on a circuit board that’s only 8.5” long. Identical in other ways to MSI’s PCB, the 8.6” distance between the slot plate and the end of its PCIe power connector allows reasonable cable clearance in tight cases. A plastic cover over the card's cooling fan extends its total mounting depth to 8.9".

Clock rates of 820 MHz GPU and GDDR5-4400 are sure to boost the PCS+ AX6850’s frame rates to performance levels not consistently supported by MSI’s similar three-phase design. A slightly larger heat sink keeps things cool under the added load.

PowerColor does not yet offer an overclocking utility for its Radeon HD 6850 cards, but users can always try one from a third party.

Registration gets PCS+ AX6850 buyers a month of VIP access to SuperStar Racing, an online multiplayer formula racing game.

Sapphire does things its own way, beginning with an oversized blow-through cooler on its part number 100315TXSR Toxic 6850.

Sapphire buyers get a surprising array of upgrades, from the card’s dual mini-DisplayPort outputs (and single full-sized adapter) to its inclusion of a six-foot HDMI cable. Sapphire even throws in two four-pin Molex to six-pin PCIe power adapter cables.

The dual power adapters make sense in light of the fact that Sapphire puts two six-pin PCIe power connectors on its card. Sapphire’s entire design is borrowed from the Radeon HD 6870, stretching the card to a 9.6” mounted length, while adding the handy feature of a card that vents out the back of the case.

Even though Sapphire’s Toxic 6850 is oversized, it uses the same 820 MHz GPU and GDDR5-4400 clocks as the smaller PowerColor competitor in today’s comparison. Rather than include software, Sapphire adds onboard features and cables to make its Toxic 6850 unique.

Sapphire doesn’t have an overclocking utility for its 6850 cards, though third-party utilities often support this model

Test System Configuration
CPUIntel Core i7-980X (3.33 GHz, 12 MB Shared L3 Cache)
Overclocked to 4 GHz at +100 mV, 160 MHz BCLK
MotherboardGigabyte X58A-UD9 BIOS F3 (05/28/2010)
Intel X58 Express, LGA 1366
RAMKingston KHX16000D3ULT1K3/6GX (6 GB)
DDR3-2000 at DDR3-1600 CAS 7-7-7-21
OS Hard DriveWestern Digital Velociraptor WD3000HLFS, 300 GB
10 000 RPM, SATA 3Gb/s, 16 MB cache
SoundIntegrated HD Audio
NetworkIntegrated Gigabit Networking
PowerOCZ-Z1000M 1000 W Modular, ATX12V v2.2, EPS12V, 80 PLUS Gold
OSMicrosoft Windows 7 Ultimate 64-bit
GeForce GraphicsForceWare 258.96
Radeon GraphicsAMD Catalyst 10.10
ChipsetIntel INF

Gigabyte’s four-way CrossFire/SLI-supporting motherboard provides today’s test cards with all the performance they need, while opening up the possibility of future CrossFire scaling articles using some of today’s data.
Clock speed has often been our biggest bottleneck in achieving full graphics card performance. None of our games require more than three processing cores, yet Intel’s six-core Core i7-980X is already in the board and easily supports 4 GHz overclocked.

OCZ’s Z1000M provides over 88% efficiency across a very broad range of loads, at minimal noise.

Benchmark Configuration
3D Games
Aliens Vs. Predator BenchmarkAlien vs Predator Benchmark Tool
Test Set 1: Highest Settings, No AA
Test Set 2: Highest Settings, 4x AA
Call of Duty: Modern Warfare 2Campaign, Act III, Second Sun (45 sec. FRAPS)
Test Set 1: Highest Settings, No AA
Test Set 2: Highest Settings, 4x AA
CrysisPatch 1.2.1, DirectX 10, 64-bit executable, benchmark tool
Test Set 1: Highest Quality, No AA
Test Set 2: Highest Quality, 4x AA
DiRT 2Run with -benchmark example_benchmark.xml
Test Set 1: Highest Settings, No AA
Test Set 2: Highest Settings, 4x AA
S.T.A.L.K.E.R.: Call Of PripyatCall Of Pripyat Benchmark version
Test Set 1: Highest Settings, No AA
Test Set 2: Highest Settings, 4x MSAA
Synthetic Benchmarks and Settings
3DMark VantageVersion: 1.0.1, GPU and CPU scores
Power, Heat, and Noise
GPU LoadFurMark 1.6.5 Stability Test, 1920x1200, 4x AA
P3 Kill A Watt P4400Global Power Consumption at AC outlet
Galaxy Check Mate CM-140Measured at 1/4 meter, corrected to 1 m (-12 db)

This author’s argument against definitive noise measurements is that it’s almost impossible to remove background noise contamination from a running system. Yet, many readers insist that these measurements must be taken for relativity's sake. Using a “supersized” CPU air cooler that takes several minutes to warm up, the CPU fan has been temporarily disconnected during sound tests to get a somewhat-close approximation of each card’s true noise level.

The Call of Pripyat benchmark has, in the past, been an exceedingly strenuous workload for mid-range graphics cards. And yet, all four Radeon HD 6850s breeze through our 1680x1050 test.

Slow frame rates at our target 1920x1080 resolution with 4x AA enabled force us again to look at test notes. Sapphire and PowerColor each had a minimum 20 FPS, while Asus and MSI dropped to 19 and 18 FPS, respectively.

All four cards appear playable at 2560x1600, yet another look at our test notes showed a failing 14-15 FPS minimum for every card, with AA disabled. You're simply going to want something faster to play this game at these settings.

3DMark scores don’t mean much in the real world, but we did notice the scores in today’s Radeon HD 6850 roundup are very similar to those generated in our previous GeForce GTX 460 reviews. That similarity is partly due to disabling the PPU test, which we feel gives Nvidia an artificial and unrealistic advantage.

Voltage and clock speed have adverse effects on power consumption, so we expect the fastest cards to fall to the bottom of our power chart.

Asus has surprisingly low power consumption compared to MSI, and even the slightest power advantage for Sapphire’s oversized card surprises us when compared to PowerColor. We wonder why Sapphire needed to include two PCIe connectors?

Sapphire edges out PowerColor in average frame rate, but margins this small could be pure variance.
This is where our match gets tedious. We wanted to base our efficiency number purely on averages, so we first averaged the No AA and 4x AA average frame rates of each card. We then calculated a class average by averaging our list of averages. For those following along, the class average is 49.8 FPS.
Dividing each card’s average by the class average puts its performance level on a percent scale, where “zero difference” is actually 100% and the top cards are higher. Following the same procedure for Full Load and Idle power gives us a similar percent scale where the most miserly cards have the lowest score. Dividing those results gives use a calculation of efficiency, where class average is 100%.

Yet no electronic component is 100% efficient. We subtracted 1 from each card’s result to move the chart scale by 100%, focusing only on the differences in efficiency. Asus’ lower-power “mid-speed” card is 3.9% more efficient than the class average, while Sapphire’s moderate power consumption makes it the most efficient “fast” card.

Heat and noise output are controlled not just by the GPU voltage and clock, but by the cooler design. Asus surprised us by having the lowest temperature, since the card was also relatively quiet. Sapphire takes second place when its fan is turned to max speed.

Quiet coolers are often sub-par when dealing with heat, but Asus proved the contrary with its DirectCU design. The chart below is not perfectly accurate, since some background noise was unavoidable.

Sapphire has the noisiest card. But looking beyond the card itself, there is an advantage to its noisier, blower-type fan. That advantage is case cooling, since the Sapphire Toxic 6850 is the only card in today’s comparison to vent most of its heat outside of the case. We’ve previously seen the consequences of using internally-vented cards in an extreme CPU configuration.

Following a similar method to that of our previous-page’s energy efficiency calculations, we compared temperature to noise for today’s cards. Note that the temperature division is “flipped over” in this case to give the lowest temperature the highest score, and that the “acoustic efficiency” chart does not account for performance differences.

Sapphire and PowerColor have the best-performing graphics cards, but who has the best performance-value? We averaged the price of all four cards, then divided the actual price by the class average to put each card on a percent scale.

Based solely on a comparison of price to performance, Asus wins. Yet, unlike PowerColor, Asus does not include a free game certificate with its card. If you don't already own Call of Duty and that bundled item is important to you, then the balance shifts toward PowerColor's offering. Likewise, Sapphire is the only company to include a free HDMI cable with its card. So if the card is going into a home theater environment and you're missing HDMI connectivity, Sapphire's inclusion is more meaningful. Both Sapphire and PowerColor provide marginally better performance than Asus, and the packaged bonus features for both Sapphire and PowerColor come at a mere $10 price premium compared to Asus.
So, which card would we chose? This tester would probably pick the Asus EAH6850 DirectCU Overclock Edition for its low noise. But then again this tester already has HDMI cables and more game licenses than he can ever use.
If this was a System Builder Marathon, I’d probably go with two Sapphire Toxic 6850 cards for their externally-vented design. Pushing graphics heat out of the case would allow a more aggressive CPU overclock, and the CPU is a big bottleneck in multiple-GPU configurations.
If I were building for someone else, I would probably choose the PowerColor PCS+ AX6850 for its high speed, moderately-low noise, and free game. That special someone would probably value the extra software worth anywhere from thirty to fifty dollars online. Now, where did I put that Christmas list?

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