Michael Brown writes:
"Need a new videocard, but don't have the Benjamins-or the need-for a high-end model? Take a look at some of the new budget cards, such as AMD's ATI Radeon HD 4600 series: AMD's latest videocards promise to deliver decent gaming performance-and 512 MB frame buffers-for as little as $69
AMD has so far announced two SKUs in this series: The Radeon HD 4650 ($69) and the Radeon HD 4670 ($79). The company plans to ship a third model, which will be outfitted with 1GB of memory, later this month. Both announced cards have the same GPU, which boasts 320 stream-processing units, but a relatively narrow 128-bit memory interface (AMD's pricier parts have 256-bit memory interfaces, and Nvidia's top-end GPU has a 512-bit memory interfaces). The 4650's core clock speed will be set at 600 MHz (compared to the 4670's 750 MHz).
This is one case where overclocking the cheaper card to achieve the same performance as the more expensive model isn't going to work: The higher-priced 4670 features GDDR3 memory clocked at 1GHz, but the cheaper model rolls with GDDR2 memory running at just 500MHz. No amount of tweaking is going to compensate for that architectural disadvantage."