It seems that AMD has begun shipping its first Radeon HD 4000-series video chipset. The ATI Radeon HD 4850 is purportedly already on its way to card manufacturers and stores, and will represent a significant boost to the clock speed of the earlier, mid-range 3850 without affecting its heat; the core speed jumps from 670MHz to 800MHz while still occupying a single card slot.

Pricing is still a contentious point, those who claim to be aware of AMD's plans say. The company may wait until the day of the announcement itself to set a price and has given itself a price range between $179 and $219 for a stock card with 512MB of video memory. A last-minute price choice will purportedly let AMD meet an expected June 18th real-world launch without having to adjust costs ahead of time.

The uncertainty over the pricing and the launch date also likely reflect a same-day release of NVIDIA's upcoming GeForce GTX, which will initially target the high end but should create pressure on AMD to make its lower-cost cards more affordable.

Higher-end cards from AMD, including the Radeon HD 4870 and the 4870 X2, are expected to ship later in the summer.