Radeon X1950 XT is a high-end GPU based on the 80nm variant of the R500 architecture.
It's based on the R580+ Core and offers 48 Pixel Shaders, 16 TMUs and 16 ROPs, on a 256-bit of standard GDDR3. The central unit runs at 625MHz and the memory clock operates at up to 900MHz.
Its therefore a slightly underclocked Radeon X1900 XTX that's slightly slower and heats less, due to the small manufacturing process.
Most of today's games might be playable at medium settings although the low preset will have to suffice on some. As it's not based on a Shader-Unified architecture, both DirectX 10 & 11 games aren't supported.