NVIDIA and AMD/ATI routinely fight it out in the video card market for dominance and the gamers dollar. Recently NVIDIA has been producing the better performing video cards, but AMD is back with a new family of GPUs selling at low prices that it hopes will grab some of NVIDIA’s market.

AMD announced officially today its Radeon HD 4800 series video cards with 800 processing cores. The HD 4850 carries a retail price of $199 and has a stock GPU speed of 625 MHz. Memory for the card is 512MB of GDDR3. AMD says that the GPU in the card can deliver a teraflop of computing power.

Windows computer users take for granted for the most part that you can upgrade your video card with ease. That is assuming you didn’t buy a factory built system that uses a small case or proprietary video card design. Mac users on the other hand are traditionally mostly limited to the video card that ships in their Mac system.

AMD announced a new ATI Radeon HD3870 video card that is optimized for use on the Mac, but retains its PC compatibility as well. The card is called the ATI Radeon HD 3870 for Mac & PC Edition. The card has a 256-bit memory interface and has 512MB of GDDR4 and 320 stream processors.

Diamond Multimedia, a maker of PC graphics cards and other products, announced today PCI Express 2.0 graphics cards which host new AMD/ATI graphics CPUs. The Radeon HD3850 and HD3870 cards are priced at around $180 and $230 respectively.

The ATI Radeon HD3850 card is what is described as the single slot core model with 256MB of DDR3 memory and a clock speed of 668 MHz. The HD3870 is the dual slot version, with 512MB of DDR4 memory and a clock speed of 775 MHz. The HD3800 series, as this cards are known as, uses ATI CrossFireX multi-GPU technology “to simplify installation of up to four compatible cards.”