Test Drive Unlimited
With Test Drive Unlimited, the superiority of the Radeon HD 4870 X2 is less pronounced due to the lack of a CrossFireX profile. As a result, the card behaves like a 1 GB Radeon HD 4870 here, with its advantage over the 512 MB Radeon HD 4870 not exceeding 11%. This is enough, however, to place it in front of the GeForce GTX 280, but only when the anti-aliasing is activated.
The Radeon HD 4870 X2 hits the target with Crysis, which has become a playable game for the first time at 2560x1600. It’s here that the presence of 2 GB of total memory (1 GB that’s actually usable, just as a reminder) has proven itself to be rewarding. The Radeon HD 4870 X2 turns out to be more than two times faster than the Radeon HD 4870 (with the exception, as always of 1920*1200). Its advantage over the GeForce GTX 280 comes in at 77% in 2560x1600, and increases even more to 118% once the anti-aliasing is activated, even if this mode remains unplayable.
The older 3870 X2, with its 512 MB of memory per graphics processor, isn’t able to outperform the Radeon HD 4870 despite its superior horsepower and the same drivers. This shows that the behavior of a bi-GPU card depends quite a bit on its design.