Radeon HD 4870 X2: Four Cards Compared

Radeon HD 4870 And HD 4870 X2 Compared

In the following direct comparisons, we will provide a more detailed analysis of the advantages of the X2 for different games and resolutions. In this analysis, we compare the frame rates (fps) and give them as a percentage that shows the gain or drop in performance in each case. The first comparison addresses the old question: is a single-chip card enough, do you need CrossFire, and how much do you gain from a second graphics chip?

Assassin’s Creed runs absolutely perfectly with the Radeon HD 4870. A slight increase can only be seen above 1920x1200 pixels with anti-aliasing. But you don’t really need a dual-chip card when the boost is only 12.6%.

Call of Duty 4 can be played smoothly with a single-chip card. The dual-chip card raises performance to a whole new level, though—the gain of 62% to over 100% is gigantic and there should not be any shakiness left even in missions with heavy graphics demands.

In Crysis, a dual-chip card pays off in high resolutions with anti-aliasing turned on. After more than a month of optimizing CrossFire, Crysis has finally become faster and benefits from the two HD 4870 X2 GPUs. At lower resolutions, the CPU limits performance, determining the maximum frame rate.

With the highest picture quality and anti-aliasing, you really need twice the graphics power. The gain at higher resolutions with AA is increased even more through the larger graphics memory of 2 x1 GB, which is the reference spec for AMD’s Radeon HD 4870 X2. If you have a Radeon HD 4870 with 1 GB of graphics memory, the difference in going to the X2 will be smaller. The values shown in the table are limited by the 512 MB test card.

The id engine employing OpenGL responds well to CPU power. The graphics card has less of an impact, so a single chip is enough for this game.

The Source engine used to drive Half Life 2 responds more to CPU performance, getting hardly any advantage from the dual-chip Radeon HD 4870 X2.

Mass Effect, with the UT3 engine, scales very nicely with the graphics processors (GPUs) used. The gain can be up to 80%. The game runs smoothly only with the dual-chip card, especially with anti-aliasing.

Flight Simulator is unable to take advantage of two-card configurations and consequently doesn’t demonstrate any gain at all.

World in Conflict without anti-aliasing responds more to CPU speed. With anti-aliasing turned on, the Radeon HD 4870 X2 gains performance, but only pays off at resolutions above 1680x1050 or 1920x1200. Below that, it’s subjectively a waste.