AMD and NVIDIA usually do not launch graphics cards on the same day, but today is a new day and that is exactly what has happened. AMD is announcing the Radeon HD 4890 graphics card, which is powered by the RV790 GPU. This is basically an updated and improved version of the RV770 which powers the Radeon HD 4870 and 4850 series of video cards. Arch rival NVIDIA is releasing the GeForce GTX 275 graphics card. This graphics card is basically half of a GeForce GTX 295 and it has been overclocked for even better performance than the GeForce GTX 260. Neither of the cards has been designed from the ground up with truly new designs, but both feature improvements in a number of areas that are important to consumers.
The RV790 is a re-masked RV770 that has been improved upon. AMD basically took a look at the RV770 and figured out what could be done better to improve thermals and power consumption, while at the same time boosting the clock frequencies. When the dust settled AMD had a new chip they named RV790. This new GPU has 3 million more transistors than the old one due to changes in the decap Ring (signal noise/die area), retiming of entire chip, and altered ASIC power distribution. With that many new transistors you can see that AMD really did change a ton of things and they claim the new chip is an overclocking monster. They also updated the PCB design, improved the heat sink by adding a heat pipe, and have improved drivers since the launch of the original RV770.
As a result, the base clocks for the Radeon HD 4890 will be 850MHz for the GPU and 975MHz for the GDDR5 memory. They also have a Radeon HD 4890 OC, which has a higher core clock of 900MHz. If that isn’t fast enough, AMD claims that these graphics cards can easily reach just shy of 1GHz on the core and 1050MHz+ on the memory without touching the voltages. If you wanted to tinker with the voltages and add a better cooling solution, AMD claims you might even be able to reach higher! When it comes to pricing AMD told Legit Reviews today that the Radeon HD 4890 1GB graphics card will sell for ”under $260”, but they expect that you will find them for under $220 after mail-in-rebate. They also said that retailers have them already, so by the time you read this you should be able to order one. No paper launch going on with AMD, so let’s take a look at what NVIDIA is doing today.
The GeForce GTX 275 is based on the GT200 architecture, featuring 240 shader processors operating at 1404MHz. In price and performance, the card sits between the GeForce GTX 260 core 216 and the GeForce GTX 285. In all honesty, the GeForce GTX 275 isn’t that far off from a GTX 285 as the 448-bit memory interface is just shy from the full 512-bit interface. The GeForce GTX 275 also differs from the GeForce GTX 285 as it has two fewer memory ICs, so it has a total frame buffer size of 896MB instead of the 1GB. NVIDIA is eager to inform the consumers that the GeForce GTX 275 is fundamentally differentiated from the Radeon HD 4890 by supporting PhysX, CUDA, and GeForce 3D Vision, but our readers already should know that. The GeForce GTX 275 is supposed to retail around the $249 USD range with retail availability expected on or before April 14, 2009.
Let’s take a closer look at the cards and head to the performance numbers!