XFX HD7870 Double Dissipation Black Edition - pretty much faultless

The 7800 series seems to have come out of nowhere. It seemed like one day AMD were knocking on our door with a reference design card, and literally the next a shiny new XFX 7870 was waiting for us in our labs. The delay between engineering samples and actual retail product was almost non-existent which suggests that yields are high, and so is the confidence over at AMD.

As this is the first 7870 to appear on our pages, let's take some time to go over exactly what the 7870 is, and why it's such a great option for gamers on 1920x1200 screens. Essentially, this is just a "dumbed down" version of the HD 7950 (who'd have thought?) with a smaller core count and reduced memory bandwidth. The feature list however, is identical, offering all of the same features and technologies of the superior 7900 series.

Of course one of the most important gains this card has over the old 6970 is the new GCN architecture, providing up to 400% greater tessellation performance in some situations, and simply destroying the heaven benchmark compared to the video cards of old. This essentially means the 7870 card is the perfect replacement for the 6970, offering far greater performance, and due to the awesome yields AMD are experiencing, it does so at a price more than fair (even in Australia).

The card and cooler are a striking resemblance of the 7900 series from XFX, but that is not a bad thing. We love this cooler, and if it can help keep temperatures and prices down for XFX on the 7800 series as well, we have no issues with them re-using this cooler.

The 28nm core on this model is set to 1050MHz and the 2GB of Hynix GDDR5 memory is set to 1250MHz, both 50MHz bumps over reference. For the Stream processors AMD have gone for a 1280 core/32ROP design and a memory bus of 256-bit. PCIe 3.0, DirectX 11.1 and DirectCompute are all supported on this card, as is acceleration of high definition video content, and the card can output 7.1 audio over HDMI including DTS Master Audio and Dolby TrueHD.

The card is powered by two 6-pin power connectors, giving the card a theoretical maximum power ceiling of 250W (not that it will ever use anywhere close to that). Regular power use seems to fall around 240W on our test system (3960X and four 1.65V RAM sticks), so it is noticeably lower than the 7970 and 7950. We'd hazard a guess as to around 150W is maximum power drawn from this card.

Overclocking on the 7800 series is a simple process; we open Afterburner, and from there we can begin moving the sliders to our desired speed, and even tweak voltages for additional stability at a cost of heat.

It seems the overclock to aim for on 7870 cards is 1250MHz core and 1450MHz memory, and our XFX sample reviewed today managed to go slightly higher. 1260MHz was reached on the core, and the memory reached a clock of 1500MHz without any problems at all. This brings performance up to the levels of a stock 7950, which in our opinion is a great success.

Looking to the build quality and design of this card, it is clear that both XFX have improved on the reference design cards that AMD first launched. In this case XFX have used what appears to be a custom PCB with the much improved dual fan cooler. Essentially we can't fault the card, and for the price we are certainly happy with the results