X-bit labs

There Will Be Speed: The Clash of Modern Multi-GPU Technologies (page 10)

Category: Video

by Alexey Stepin , Yaroslav Lyssenko, Anton Shilov

[ 03/24/2008 | 05:01 PM ]

Testbed and Methods

To test the gaming performance of contemporary multi-GPU platforms we put together the following testbeds:

• Intel Core 2 Extreme X6800 processor (3.0GHz, FSB 1333MHz x 9);  
• DFI LANParty UT ICFX3200-T2R/G (ATI CrossFire Xpress 3200 chipset) for ATI Radeon?CrossFireX;
• Asus P5N32-E SLI mainboard (Nvidia nForce 680i SLI chipset) for Nvidia GeForce/Quad SLI;
• Corsair TWIN2X2048-8500C5 (2x1GB, 1066MHz, 5-5-5-15, 2T);
• Maxtor MaXLine III 7B250S0 HDD (250GB, Serial ATA-150, 16MB buffer);
• Enermax Galaxy DXX EGX1000EWL 1000W power supply;
• Dell 3007WFP monitor (30", 2560x1600@60Hz max display resolution);
• Microsoft Windows Vista Ultimate 32-bit;
• ATI Catalyst 8.3 for Radeon HD 3870/HD 3870 X2/HD 3870 3-way/4-way CrossFireX;
• Nvidia ForceWare 169.25 WHQL for GeForce 8800 GTS 512MB;
• Nvidia ForceWare 174.53 WHQL for GeForce 9800 GX2/GeForce 9800 GX2 Quad SLI.

According to our testing methodology, the drivers were set up to provide the highest possible quality of texture filtering and to minimize the effect of software optimizations used by default by both: AMD/ATI and Nvidia. Also, to ensure maximum image quality, we enabled transparent texture filtering - Adaptive Anti-Aliasing/Multi-sampling for ATI Catalyst and Antialiasing – Transparency: Multisampling for Nvidia ForceWare. As a result, our ATI and Nvidia driver settings looked as follows:

ATI Catalyst:

• Catalyst A.I.: Standard
• Mipmap Detail Level: High Quality
• High Quality AF: On
• Wait for vertical refresh: Always Off
• Enable Adaptive Anti-Aliasing: On/Quality
• Method: Multi-sampling
• Temporal Anti-Aliasing: Off
• Other settings: default

Nvidia ForceWare:

• Texture filtering - Quality: High quality
• Texture filtering - Trilinear optimization: Off
• Texture filtering – Anisotropic sample optimization: Off
• Vertical sync: Force off
• Antialiasing - Gamma correction: On
• Antialiasing - Transparency: Multisampling
• Other settings: default

For our tests we used the following games and benchmarks:

First-Person 3D Shooters

• Battlefield 2142
• Bioshock
• Call of Juarez
• Call of Duty 4
• Crysis
• Enemy Territory: Quake Wars
• Half-Life 2: Episode Two
• S.T.A.L.K.E.R.: Shadow of Chernobyl

Third-Person 3D Shooters

• Lost Planet: Extreme Condition
• Tomb Raider: Legend

RPG

• Hellgate: London
• The Elder Scrolls IV: Oblivion

Strategies

• Company of Heroes: Opposing Fronts
• Command & Conquer 3: Tiberium Wars
• World in Conflict

Synthetic Benchmarks

• Futuremark 3DMark05
• Futuremark 3DMark06

We selected the highest possible level of detail in each game using standard tools provided by the game itself from the gaming menu. The games configuration files weren’t modified in any way. The only exception was Enemy Territory: Quake Wars game where we disabled the built-in fps rate limitation locked at 30fps. Games supporting DirectX 10 were tested in this particular mode.

Besides Nvidia GeForce 9800 GX2 we have also included the results for the following single graphics accelerators:

• ATI Radeon HD 3870 X2 (2xRV670, 825/825/1800MHz, 640sp, 32tmu, 32rop, 2x256-bit, 2x512MB GDDR3)
• ATI Radeon HD 3870 (RV670, 775/2250MHz, 320sp, 16tmu, 16rop, 256-bit, 512MB GDDR4)
• Nvidia GeForce 8800 GTS 512MB (G92, 650/1620/1940MHz, 128sp, 32tmu, 16rop, 256-bit, 512MB GDDR3)

Since this article is devoted not only to Nvidia GeForce 9800 GX2, but also to contemporary multi-GPU platforms in general, we have also tested the performance of the following configurations:

• ATI Radeon HD 3870 3-way CrossFireX (ATI Radeon HD 3870 X2 + ATI Radeon HD 3870)
• ATI Radeon HD 3870 4-way CrossFireX (2xATI Radeon HD 3870 X2)
• Nvidia GeForce 9800 GX2 Quad SLI (2xGeForce 9800 GX2: Gainward Bliss 9800 GX2, Zotac 9800 GX2)

The tests were performed in the following resolutions: 1280x1024/960, 1600x1200, 1920x1200 and 2560x1600. If the game didn’t support 16:10 display format, we set the last resolutions to 1920x1440 and 2048x1536 respectively.

Single graphics cards were not tested in resolutions beyond 1920x1200 because they are evidently unable to ensure acceptable performance in most cases. At the same time, we didn’t test multi-processor configurations in 1280x1024, since they will not be able to reveal their potential in this resolution because of CPU limitations.

We used “eye candy” mode everywhere, where it was possible without disabling the HDR/Shader Model 3.0/Shader Model 4.0. Namely, we ran the tests with enabled anisotropic filtering 16x as well as MSAA 4x antialiasing. We enabled them from the game’s menu. If this was not possible, we forced them using the appropriate driver settings of ATI Catalyst and Nvidia ForceWare drivers. Performance was measured with the games’ own tools and the original demos were recorded if possible. Otherwise, the performance was measured manually with Fraps utility version 2.9.1. We measured not only the average speed, but also the minimum speed of the cards where possible.