Advanced Micro Devices and Nvidia on Thursday launched competing graphics cards that the companies claim offer the best performance for the price.

AMD introduced the ATI Radeon HD 4890 and Nvidia unveiled the GeForce GTX 275. Both cards sell for less than $260 and are aimed at PC gamers.

The AMD product has an 850-MHz core clock speed, a memory clock speed of 975 MHz, and 1 GB of GDDR5 memory. The card has a maximum board power of 190 watts and consumes 60 watts during idle. The Radeon HD 4890 GPU is available through AMD partner products. Diamond Multimedia, for example, is selling on NewEgg.com a card based on the AMD processor for $230, after a $20 mail-in rebate.

The Nvidia card features 240 processor cores operating at 1,404 MHz, 80 texture processing units, a 448-bit memory interface, and an 896-MB frame buffer. In terms of price and performance, it sits between the GeForce GTX 260 and GTX 285. The card is scheduled to be available April 14, and Nvidia said it offers the best performance among products in the $229 to $249 price range.

While it's not unusual for vendors to claim to offer the best deal, some comparisons of the two products have been done. ExtremeTech has tested Nvidia's card against an Asus Radeon HD 4890 card.

In terms of running games, neither product presented as good a value as the vendors' current batch of $200 cards that the latest products are supposed to displace, the gamers' site said.

"The new cards, at around $250, are roughly 25% more expensive than the $200 GeForce GTX 260 c216 and Radeon HD 4870, but they're not 25% faster," the ExtremeTech review said. "You get more bang for your buck -- if less absolute bang -- with the less expensive cards."

Overall, the site gave each of the new cards a "very good" rating.

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