A Closer Look

You may combine two of these cards in CrossFire for increased performance or better image quality. It is also possible to add a single HD 4870 for triple CrossFire.


The card has one six-pin power connector and one eight-pin power connector. Both are required for operation.


The GDDR5 memory chips are made by Qimonda and carry the model number IDGV1G-05A1F1C-40X. With a latency of 1.0 ns, they should be good for at least 1000 MHz.


The PLX Technology PEX 8647 is a PCIe Gen2, 5.0GT/s 48-lane, 3-port PCIe Switch.
While the bridge chip on the HD 3870 X2 supported only PCI-E 1.1 transfers, this one has full support for PCI-E 2.0, and also offers new features like Dual Cast and Read Pacing.


Two AMD RV770 GPUs are working together on the HD 4870 X2. The GPU has a die size of 256 mm², is made in a 55 nm process and sports 956 million transistors.