The HD- 4000 series of the 55nm fabrication process and the fastest and the cheapest cards you can buy and play the most games like Crysis and any other DX 10 games with the most fats pace and also the hungriest card you have to really buy and experience yourself. And also, another card is going to make a debut also to the HD-4000 name with the support of DX10.0 revision and also keep up with the demand of mainstream and hybrid money can buy graphics. So the 4890 is just another card that is between the 4870 1 GB version and also the next high dual card the 4850X2.
PCI special interest group has certified compatibility of the yet-not-announced code-named ATI RV790 graphics processor with the PCI Express 2.0 bus. Such certification indirectly confirms that the graphics card currently known as the Radeon HD 4890 is about to be released commercial
According to industrial sources with knowledge of the matter, the code-named ATI RV790 graphics processing unit is nothing else but the already shipping ATI RV770 chip with higher clock-speeds. The new processor can operate at higher frequencies since its design is slightly refined, certain erratums (which do not affect performance or stability of the RV770) are corrected and process technology adjustments are made.
ATI RV770/790 graphics processing units feature 800 stream processors, 40 texture units, 16 render back ends as well as 256-bit memory bus compatible with GDDR3, GDDR4 and GDDR5 memory types. The RV790 will feature higher clock-speeds, but not increased number of execution units.
Performance increases of the graphics card that is projected to be called ATI Radeon HD 4890 over the existing Radeon HD 4870 1GB should not be high as the difference between two products will be increases of clock-speeds. In case the graphics card designer decides to release ATI Radeon HD 4890 X2, performance gain should be modest as well.
We are in the final moments of this current generation of video cards, it seems. Near the end of any video card generation, ATI and NVIDIA always seem to release products that sum up everything they learned over the stretch of development.
It looks like an HD 4890 and a GTX 275 are coming, as revisions of existing HD 4870 and GTX 260 (216 shader) cards. According to VR-Zone, both cards will be around $240 USD, and will arrive in early April.
The HD 4890 looks like it will basically be a HD 4870 with a couple of tweaks, and higher clocks. The GTX 275 appears to be a GT200b based card that will be approaching GTX 280’s level of performance.
Both companies also have re-worked, cheaper cards in the pipelines. Nvidia’s has already come out: the GTS 250, which is a tweaked 9800GTX+. ATI is rumored to be about to release a HD 47xx card, which will sell for around a $100, and offer performance somewhat comparable to a HD 4830.
