We were suitably impressed when ATI released its last range of high-end graphics cards. The HD 4870, HD 4850, and HD 4870X2 all produced impressive performance and most importantly delivered it at a decent price. However, relative prices are one thing but if you simply can't afford or can't justify spending more than £50 just to play the latest 3D games then you'll be wanting something a little cheaper. Something like this ATI HD 4670, in fact.
It's based on the same basic design features of the Graphics Processing Unit (GPU) chip that lies at the heart of the 48x0 series of cards but, as you would expect considering its price, there's just less of all the processing bits inside. So, rather than 800 stream processors, the HD 4670 features just 320 and instead of 16 ROPs it has only 8. It also uses the more conventional GDDR3 memory found on the HD4850, rather than the super-fast GDDR5 memory used on the HD 4870, and the GPU talks to this memory over a 256-bit interface. Core clock speeds and memory speeds also differ though these aspects will vary depending on the exact configuration the card manufacturer's release - expect there to be plenty of exotic overclocked versions.
As well as the HD 4670, there is the HD 4650, which uses the same smaller GPU but along with lower core clock speeds, the memory type has changed to DDR2 and the interface has been reduced in width to just 128-bit.
In terms of features there's little to distinguish the HD 4670 from its more powerful brothers. As well as the 3D graphics processing elements, you get ATI's Universal Video Decoder (UVD) and Avivo video that accelerate and improve the quality of video playback. There's also support for the latest edge-detection anti-aliasing mode, which offers by far the best image quality we've seen on any graphics card.
If you're looking to spread the cost of your graphics upgrade, you can buy one of these cards now then in a few months time you can buy another one and take advantage of CrossfireX to use the power of both cards together - assuming you have a CrossfireX or SLI capable motherboard, of course.
We're always a little sceptical of these dual/multi card configurations, due to their potential problems with compatibility and stability, and if you had a choice of getting two cards or a single one for the same price we'd always recommend going for the latter. However, in such a price-sensitive market this route makes sense. I'd certainly rather buy one card now and have some gaming ability in time for Christmas, then save for a few more months and improve performance further, rather than save the entire time.