Verdict: Meet the Radeon HD 3850's big brother.
It seems that a company in AMD's precarious position has to be sensible and concentrate on sales, rather than playing 'my card's faster than yours' with Nvidia. This may be why the two latest graphics cards from the AMD/ATI camp have relatively low prices, especially considering that they're at the top of ATI's product range. Mass demand wanes beyond £200, with only the likes of CPC staff and readers interested. Therefore, as long as ATI has a decent margin on the HD 3850 and this HD 3870, there's plenty of potential for profit. A strong ATI means that Nvidia has competition, which should result in better products at better prices. Hopefully, the HD 3870 will be as good as the HD 3850.
The HD 3870 is essentially a faster and more expensive version of the HD 3850; it's based around the same GPU, so it shares all the new features of the HD 3850. This means PCI Express 2.0 support, DirectX 10.1 and Shader Model 4.1 (features that will only be activated in Vista Service Pack 1). The HD 3870 also has 320 stream processors and 16 ROPs, so it looks promising. The extra £40 over the HD 3850 nets you significant gains though. The HD 3870 has 512MB of memory as standard, double that of a standard HD 3850, and it's clocked at 1.125GHz (2.25GHz effective) rather than 829MHz (1.66GHz effective), although the HD 3870 still has a 256-bit memory bus. This memory boost should help the GPU with high-resolution gaming, which is important, as the HD 3850 has enough gaming power for 1,680 x 1,050 in most games. You'd hope the next card up in ATI's range would give enough performance for the next resolution up.
To this effect, the speed of the GPU has also been increased to 777MHz, 108MHz faster than the GPU of a reference HD 3850. The reassuringly chunky dual-slot cooler thankfully doesn't make much noise while disposing of waste heat, although it can be painfully hot to the touch in some areas. Importantly, the card remained perfectly stable during our tests. With the HD 3870 installed, our test PC drew 258W from the mains, which is a fair amount more than the Sapphire HD 3850.
The HD 3870 performed admirably for a £145 card. S.T.A.L.K.E.R. managed a perfectly playable minimum frame rate of 28fps at 1,920 by 1,200 - full detail settings on a 24in TFT monitor is very impressive. F.E.A.R. saw the HD 3870 return less impressive results, though, with a stuttery minimum frame rate of 17fps, a big drop from the silky-smooth minimum of 33fps at 1,680 x 1,050. However, Need for Speed: Carbon returned the HD 3870 to winning ways with a minimum of 29fps in our toughest test. Unfortunately, ATITool couldn't touch the clock speeds and ATI's own (and new) overclocking tool OverDrive refused to work too.
However, compared with the standard GeForce 8800GT-based Asus EN8800GT, the HD 3870 doesn't fare too well. All three games listed above were easily playable at the 1,920 x 1,200 settings with minimums of 29fps, 35fps and 33fps in F.E.A.R., Carbon and S.T.A.L.K.E.R. respectively. In short, the GeForce 8800 GT is between 5-12fps faster, which makes the crucial difference between stuttery and playable at this resolution. Considering that standard GeForce 8800 GT cards can be picked up for £160, you're getting a significantly better card for only £13 more.
When we switched to Vista, it was clear that there still isn't an affordable graphics card to run Company of Heroes at maximum settings in DirectX 10 mode. Even at 1,280 x 1,024 with no AA, the HD 3870 couldn't manage a playable minimum frame rate. The situation was even worse in Crysis, in which the card failed to deliver a maximum frame rate above 20fps at 1,024 x 768.
Conclusion
Neither of ATI's latest HD 3-series cards have the power to outperform Nvidia's 8800GT, but then again the HD 3850 is priced so competitively that this doesn't matter. However, the HD 3870 is another story entirely. It's priced very closely to the GeForce 8800 GT, but lacks the performance to match.
As such, your choice is refreshingly clear: if you can't stretch much beyond £100, the HD 3850 is the obvious choice; if you can afford to spend a little more then the GeForce 8800 GT is the card for you.
