The GeForce GTX 280 will feature 240 unified stream processors and NVIDIA claims the D10U features second generation unified shaders that perform 50% better than those found on the GeForce 9 series. The chip features a 512-bit memory bus and has 1GB GDDR3 memory.
For those with a bit less money there will be the GeForce GTX 260, this card features 192 stream processors, a 448-bit memory bus and 896MB GDDR3 memory.
GTX 280 and 260 add virtually all of the same features as GeForce 9800GTX: PCIe 2.0, OpenGL 2.1, SLI and PureVideoHD. The company also claims both cards will support two SLI-risers for 3-way SLI support.Support for DirectX 10.1 is still missing.
Unlike the upcoming AMD Radeon 4000 series, currently scheduled to launch in early June, the D10U chipset does not support DirectX extentions above 10.0. Next-generation Radeon will also ship with GDDR4 while the June GeForce refresh is confined to just GDDR3.