AMD Radeon HD 7870 review
The HD 7870 is the first card we've seen with AMD's new upper-mid-range 28nm "Pitcairn" graphics processor. It's significantly cheaper than the next card up, AMD's £350 Radeon HD 7950, and its specification is cut down to match; you get 1,280 stream processors rather than 1,792, 2GB instead of 3GB RAM and a 256-bit instead of 384-bit memory bus. The clock does run at a quick 1GHz instead of 800MHz, though.
The card is a reasonably-sized 242mm long, so you shouldn’t have a problem fitting it in your case, and needs two six-pin PCI Express power connectors. On the rear you have a dual-link DVI-I port, HDMI and twin DisplayPort adaptors, so it's possible to set up a multiple monitor configuration with some simple adaptors.
In our game tests, the HD 7870 definitely gives the HD 7950 a run for its money. In Dirt 3, which we run at 1,920 x 1,080, 4x anti-aliasing and Ultra detail, we saw 74.3fps, compared to 76.2fps from the more expensive card. Even when we connected two more monitors and created a 5,760 x 1,080 desktop in Eyefinity mode, we still saw 31.1fps from the HD 7870, which is not far off the HD 7950's 34.3fps.
The only test result which made it seem worth spending another £90 on the HD 7950 was the punishing Crysis 2 benchmark. At 1,920 x 1,080 and Ultra detail, the HD 7870 managed 28.8fps compared to 33.7fps from the HD 7950. This isn't a huge disparity, but it's the difference between smooth gameplay and dipping into jerky territory.
AMD has made a big show about the overclocking ability of the HD 7870, saying "1GHz is just the beginning", but we didn't have a great deal of luck overclocking it. We only managed to get the card up to 1.1GHz core speed, but this small 100MHz increase was still enough to bump Crysis 2 up to a smoother 33.5fps - the same as we saw with the HD 7950 at its stock speeds.
We gave AMD's Radeon HD 7950 a Best Buy award when we reviewed it in January, but the HD 7870 is almost as quick and much cheaper, so seems better value. It also stands up well to the previous generation of cards; while the AMD Radeon HD 6970 is around the same price as the HD 7870 and has similar performance, it's a bigger card and, unlike the new model, doesn't shut down most of its circuits when your screen is off, so uses more power. The HD 7870 is a fine evolution of AMD's impressive enthusiast graphics card line, and wins a Best Buy award.
|Interface||PCI Express x16|
|Slots taken up||2|
|Graphics Processor||AMD Radeon HD 7870|
|GPU clock speed||1.00GHz|
|Architecture||1,280 stream processors|
|Power leads required||2x 6-pin PCI Express|