ATI is on something of a roll with its range of 4-series graphics cards.

The Radeon HD 4850 and HD 4870, released in June 2008, were compelling enough for NVIDIA to take a hammer to the pricing of its mid-range and high-end parts.

Then the Radeon HD 4670 laid the smackdown on NVIDIA's GeForce 9500 GT and, to some extent, the higher-priced GeForce 9600 GT and GSO GPUs.

We also know that lower-priced 4-series GPUs are in the offing, completing a top-to-bottom line-up.

ATI reckons that there is still space for another mid-range GPU, and it will be the Radeon HD 4830 (RV770LE) - the name giving away much of the expected performance and price point.

Reckoned to be a cut-down Radeon HD 4850, the '30 variant is likely to ship with 640 stream processors (down from 800 SPs on HD 4850), a 256-bit memory interface, and 512MB GDDR3 memory. Clock frequencies are unknown.

As is the norm, we reckon that 4830s will consist of GPUs that fail to make the higher grade, with two sets of 'cores' shipped in a non-functioning state.

Extrapolating further, the new GPU should ship at around the £80-£89 mark, taking the fight squarely to the GeForce 9800 GT.