Bit-Tech published a review of AMD's ATI Radeon HD 4870 1GB

At anywhere between £187 and £200, including VAT, the Radeon HD 4870 1GB appears to represent pretty good value for money. It's not only cheaper (and better-performing) than the various GeForce GTX 260+ cards on the market, but it's also not that much more expensive than the pre-overclocked GeForce GTX 260s out there as well. In most scenarios, it's actually not too far behind Nvidia's GeForce GTX 280 a card that costs around £80 more.

When you compare it to the Radeon HD 4870 512MB, which retails for around £170 these days, you still appear to be getting a good buy as well. It costs around eight percent more and in some circumstances you're getting performance increases much bigger than that, even at 1,920 x 1,200€ the screen resolution this card looks to be targeting. Of course, there are scenarios where there will be little-to-no benefit, but they're to be expected anyway not all games are completely GPU bound and in those games you'll see very little benefit from a faster graphics card, period.

AMD's ATI Radeon HD 4870 1GB Review