Our testing methods
Before we go on, we should note a couple of things about our test setup.
First, sharp-eyed readers (and Nvidia fanboys) may notice that our GeForce GTX 560 Ti is an Asus model clocked at 830MHz. While that card is priced at $244.99, just $5 south of the 7850, GTX 560 Ti variants clocked as high as 900MHz can be had for $249.99. In short, one could accuse us of under-representing the 7850's chief rival somewhat.
Rest assured that wasn't our intention. AMD quoted a price range of $200-299 for the Radeon HD 7800 series when it briefed us last Tuesday, so when we got started on this review, we expected the 7850 might cost as little as $200. By the time AMD finally divulged its final pricing on Thursday afternoon, we'd already benchmarked the GTX 560 Ti and had no time to test another model. Just keep in mind that quicker GTX 560 Ti variants do exist as you're reading the benchmarks over the next few pages.
Also, our test system includes a Core i5-750—a 45-nm quad-core processor that's starting to grow a little long in the tooth. Someone in the market for a $349 card might be reasonably expected to own a faster CPU, perhaps of the Sandy Bridge variety. Once again, we would have loved to test with a faster product, but time constraints prevented us from doing so. This setup isn't a deal-breaker, though. None of the games and applications we tested are terribly CPU-bound, and as you'll see on the next few pages, faster GPUs had no trouble demarcating themselves from slower offerings. There's no indication that the Core i5-750 acted as a significant bottleneck.
As ever, we did our best to deliver clean benchmark numbers. Tests were run at least three times, and we reported the median results. Our test systems were configured like so:
|Processor||Intel Core i5-750|
|North bridge||Intel P55 Express|
|Memory size||4GB (2 DIMMs)|
|Memory type||Kingston HyperX KHX2133C9AD3X2K2/4GX
DDR3 SDRAM at 1333MHz
|Memory timings||9-9-9-24 1T|
|Chipset drivers||INF update 184.108.40.2065
Rapid Storage Technology 10.1.0.1008
|Audio||Integrated Via VT1828S
with 220.127.116.1100 drivers
|Hard drive||Western Digital Caviar Black 1TB
Samsung Spinpoint F1 HD103UJ 1TB SATA
|Power supply||Corsair HX750W 750W|
|OS||Windows 7 Ultimate x64 Edition
Service Pack 1
|Driver revision||GPU core
|Asus GeForce GTX 560 Ti DirectCU II||GeForce 295.73||830||1000||1024|
|Asus GeForce GTX 570 DirectCU II||GeForce 295.73||742||950||1280|
|Asus Radeon HD 6870 DirectCU||Catalyst 8.95.5-120224a||915||1050||1024|
|XFX Radeon HD 6950||Catalyst 8.95.5-120224a||830||1300||1024|
|Asus Radeon HD 6970 DirectCU II||Catalyst 8.95.5-120224a||890||1375||2048|
|Radeon HD 7850||Catalyst 8.95.5-120224a||860||1200||2048|
|Radeon HD 7870 GHz Edition||Catalyst 8.95.5-120224a||1000||1200||2048|
Thanks to Asus, Corsair, Kingston, Intel, Samsung, and Western Digital for helping to outfit our test rigs with some of the finest hardware available. AMD, Nvidia, and the makers of the various products supplied the graphics cards for testing, as well.
Unless otherwise specified, image quality settings for the graphics cards were left at the control panel defaults. Vertical refresh sync (vsync) was disabled for all tests.
We used the following test applications:
- Batman: Arkham City
- Battlefield 3
- Crysis 2
- The Elder Scrolls V: Skyrim
- LuxMark 1.0 Win64
- ShaderToyMark 0.2.0
- TessMark 0.3.0
- Fraps 3.4.7
- GPU-Z 0.5.8
Some further notes on our methods:
We used the Fraps utility to record frame rates while playing a 90-second sequence from the game. Although capturing frame rates while playing isn't precisely repeatable, we tried to make each run as similar as possible to all of the others. We tested each Fraps sequence five times per video card in order to counteract any variability. We've included frame-by-frame results from Fraps for each game, and in those plots, you're seeing the results from a single, representative pass through the test sequence.
We measured total system power consumption at the wall socket using a P3 Kill A Watt digital power meter. The monitor was plugged into a separate outlet, so its power draw was not part of our measurement. The cards were plugged into a motherboard on an open test bench.
The idle measurements were taken at the Windows desktop with the Aero theme enabled. The cards were tested under load running Skyrim at its Ultra quality preset with FXAA enabled.
We measured noise levels on our test system, sitting on an open test bench, using a TES-52 digital sound level meter. The meter was held approximately 8" from the test system at a height even with the top of the video card.
You can think of these noise level measurements much like our system power consumption tests, because the entire systems' noise levels were measured. Of course, noise levels will vary greatly in the real world along with the acoustic properties of the PC enclosure used, whether the enclosure provides adequate cooling to avoid a card's highest fan speeds, placement of the enclosure in the room, and a whole range of other variables. These results should give a reasonably good picture of comparative fan noise, though.
We used GPU-Z to log GPU temperatures during our load testing.
The tests and methods we employ are generally publicly available and reproducible. If you have questions about our methods, hit our forums to talk with us about them.