ATI Radeon HD 3870 X2 - Fastest Yet!


Very naturally, the cooling system uses two slots and sends the air out of the case. The radial fan is actually the same as the one found on the HD 2900 XT (who said ouch?). The air flow cools the first then the second GPU, both having their own sets of fin mounted on top of them. The first heat sink is aluminum in order to have the second GPU, which is paired with a copper heat sink, profit from cooler air (aluminum conducting less heat and being cheaper and lighter).

Disassembled card: lots of screw and heat sinks

The number of thermal pads is impressive

One GPU will be less efficiently cooled because of this trick, but this was also the case for the 7950 GX2 (one fan was sandwiched, which led to big gaps in temperature). Multi cards solution keep the upper hand on the subject. According to us, it would have been more interesting to place the fan in the center like on the GeForce 7800 GTX 512 MB.

The CrossFire bridge

... is placed between the two GPU

Technically, this Radeon HD 3870 X2 can really be understood as a CrossFire of two HD 3870 on a single PCB. The card only integrates a PCI Express 1.1 bridge to connect the two GPUs. They communicate via a bidirectional bus that has 16 lines for a bandwidth of 2 x 4 Gb/s. Even the access time shouldn't be significantly lower than that of a classic CrossFire solutions based on two distinct cards. Thus, this explains why we'll have to wait for drivers supporting Quad-CrossFire to pair two Radeon HD 3870 X2 on a single motherboard. On the other hand, a chipset supporting CrossFire isn't required to make this card work.

The Card (front)

The Card (back)

Equipped, as were its predecessors, with two power supply auxiliary connectors (a 6 and a 8 pin), the card only demands the use of two 6 pin PCI Express connectors (but not less, contrary to what AMD indicates, or else booting is impossible).

The PowerColor Card

Powercolor has also shipped us a sample. It's not a surprise that the card follows the reference design and is offered without any software, but with Molex adapter to PCI Express 6 pins and two adapters, DVI to VGA and DVI to HDMI, the Crossfire bridge and video out cable.