Today AMD announced their newest Radeon HD 4890 series. It is based on their RV790 GPU which is an improved version of the RV770 chipset. And the major cornerstone specifications have remained the same, only improvements related to clock frequencies have been made. While it was almost impossible to get an RV770 to run far beyond 800MHz, the new ATI Radeon HD 4890 reference runs at 850MHz core by default. Many partners will be offering overclocked boards as well ranging up to 1000MHz core speeds. Now while AMD has been sending out overclocked cards running at 900MHz, our graphics cards are just based on the reference design clocks of 850MHz though can be overclocked. - techPowerUp

Sapphire Radeon HD 4890 1GB Graphics Card Review

We received the card from Sapphire in an unprinted brown box, though the final package will just be coming in their usual bleu-ish design box. Sapphire uses the AMD reference design PCB and cooler with their own sticker on it. Though on the sample we received, the final artwork is not present. The card has two DVI ports, the most common output configuration today. If you want to use the board with your big TV screen you can use the included HDMI adapter. In case you need an analog port you can also use the included DVI adapter. The Radeon HD 4890 supports up to quad CrossFire configurations for improved performance.

AMD's Radeon HD 4890 cooler is very similar to that of the Radeon HD 4870. It uses a copper base plate that is connected to a bigger heatsink via heatpipes. The fan design exhausts hot air outside of the case. Two 6-pin power connectors are present on the reference design, where both are required for operation of the card. The GDDR5 memory chips are made by Qimonda and carry a cycle time of 1.0ns, they are specified to run at 4000MHz effective. These AMD Radeon HD 4890 series are a solid upgrade from the Radeon HD 4870. It is sad that whoever chose the fan speed settings of the Radeon HD 4890 must have been deaf.

The video card is very noisy in both idle and load, despite running at comfortable temperatures. AMD has been working on the Radeon HD 4890 pricing until a few hours ago. The latest information we received them was that the board will cost $229 after rebate. At this price the Radeon HD 4890 just can't compete with the GeForce GTX 275 when it comes to performance per dollar. AMD has been praising the overclockability of their RV790, but it seems we were unlucky with the cards we received. Our guess is that an aggressive binning strategy put the best versions on the press samples that AMD sent out.