IntroductionNVIDIA's recent introduction of NV43, and a flagship product based around it, has shaken up the mid-range performance graphics sector. Out-classing and out-pacing the previous performance champions - ATI's Radeon 9800 XT and NVIDIA GeForce FX 5950 Ultra - the GeForce 6600 GT has set the initial pace for new mid-range hardware. Today is ATI's attempt to overtake, introducing a new ASIC and new board design in their push to do so.
Like NV43 compared to NV40, ATI's new ASIC for the mid-range space, RV410, shares the same basic 3D feature set as the parent architecture, R420. That means support for the ps_2_b pixel shader HLSL profile in DirectX 9.0, full support for 3Dc, swappable sample grids for up to 6X anti-aliasing, 16X anistropic filtering, temporal anti-aliasing, the same functional units in the fragment pipeline, six vertex shader units, along with everything else.
With ATI NOT cutting out anything from the Z-buffer optimisation scheme with RV410, compared to R420, a tactic they used in previous mid-range parts to differentiate them from the high-end, the only real differentiators are in the basic fragment pipeline setup, ATI not cutting the vertex shader units in RV410 at all.
The memory bus gets tweaked to suit, with 128-bit width a transistor saving for ATI's money-making part, and RV410 sports a native PCI Express PEG16X bus link.
Thinking about RV410 in terms of R420 is quite easy; it has half the fragment shaders and 128-bit memory bus width, on a smaller die and new foundry process.
Like NV43, RV410 will power a triplet of mid-range cards, all taking the X700 name. For ATI, that's X700, X700 PRO and X700 XT, nomenclature we're familiar with these days. With rumours abound in recent times that the X700 XT would use a completely different GPU (R423 with two quads disabled), it's interesting to see the XT use the RV410 GPU.
Let's pop that into table form.