2004-05-04 ATI Radeon X800 New high end graphics chip succeeding the R350/R360 based on a completely new design also known as project Loki. Was to be shown at Comdex in November-03, but was only shown to NDA-signing people on CeBIT-04 and launched to the rest of us in May. Was earlier said to support unified DX 9.0c and Pixel and Vertex Shaders 3.0, but only DirectX 9.0b is supported.
The R420 is a simplified version of the R400 (now R500) to get a new high-end chip out quicker. R420 still uses 24 bit precision (96 bit in total) but adds 3Dc compression.
Native PCI-Express support shows up in the R423 (X800 PCI-E), formely known as X880 on June 1st.
Two versions are launched: The X800 Pro includes 12 pipelines with availability now, while the X800 XT uses 16 and ships on May 21st. A low cost X800 SE with only 8 pipelines is also planned. Previously known as R420.
2004-06-01 ATI Radeon X300 Mainstream graphics chip made in a 110 nm process. Very similar to RV380 except for lower clock speeds. Includes PCI Express support. The AGP version is called RV351, while X300 was formerly known as RV370. A version supporting Hyper Memory (sharing of primary RAM over PCIe, similar to nVidia's TurboCache) is planned for early 2005.