Introduction

Today AMD launched its much awaited Radeon HD 5800 series graphics processors. As part of our ongoing coverage that includes the main review of AMD Radeon HD HD 5870, which includes performance figures of the Radeon HD 5850, and another review on how the Radeon HD 5870 behaves with different PCI-Express configurations, in our AMD Radeon HD 5870 PCI-Express Scaling article, we have put the final piece in the puzzle with this review that covers the ATI CrossfireX multi-GPU performance scaling of two the Radeon HD 5870 accelerators, which has been possible thanks to some generous, and speedy sample assistance by ASUS. Before you proceed, make sure you have finished reading the main review which has a broader scope on the accelerator, the technologies that go into making it, and a glittering photo-shoot.



The review includes performance figures of two Radeon HD 5850 working in tandem as well. We will also be testing how running two of these accelerators with PCI-Express 2.0 x16 (electrical x8) compares to the same on the full-bandwidth interface, to try and give you a rough idea of just how viable a pair of these accelerators are, in mid-range and high-end motherboards. Finally, as with multi-GPU reviews, you will get to take a look at how the two measure up in the power consumption measurements, and whether the two are able to live up to to the great performance per watt figures unearthed from the single Radeon HD 5870. Please note, that the review will be completed in two phases. In the first phase, performance numbers of Radeon HD 5870 1 GB CrossFire will be published, which is the primary scope of this review. In the next phase, performance numbers of Radeon HD 5850 1 GB CrossFire, and Radeon HD 5870 1 GB CrossFire (PCI-Express 2.0 x16 @ x8 2.0) will be added.

Test System

• All video card results were obtained on this exact system with the exact same configuration.
• All games were set to their highest quality setting

Each benchmark was tested at the following settings and resolution:

• 1024 x 768, No Anti-aliasing. This is a standard resolution without demanding display settings.
• 1280 x 1024, 2x Anti-aliasing. Common resolution for most smaller flatscreens today (17" - 19"). A bit of eye candy turned on in the drivers.
• 1680 x 1050, 4x Anti-aliasing. Most common widescreen resolution on larger displays (19" - 22"). Very good looking driver graphics settings.
• 1920 x 1200, 4x Anti-aliasing. Typical widescreen resolution for large displays (22" - 26"). Very good looking driver graphics settings.
• 2560 x 1600, 4x Anti-aliasing. Highest possible resolution for commonly available displays (30"). Very good looking driver graphics settings.

We simulated the performance of the HD 5850 by taking our HD 5870, reducing the clock speeds and disabling two SIMDs, which results in exactly the same performance as HD 5850.

BattleForge

BattleForge, a card based RTS, is developed by the German EA Phenomic Studio. A few months after launch the game was transformed into a Play 4 Free branded game. That move and the fact that it was included as game bundle with a large number of ATI cards made it one of the more well known RTS games of 2009. You as a player assemble your deck before game to select the units that will be available. Your choice can be from forces of Fire, Frost, Nature and Shadow to complement each other.
The BattleForge engine has full support for DX 9, DX 10 and DX 10.1, we used the internal benchmark tool to acquire our results.