DirectX 8.0/8.0a
Most Notable New Feature: Shader Model 1.0, and 1.1 which introduced programmable pixel shaders (up to 12 instructions at a time) and vertex shaders. This version of DirectX is also used by Microsoft’s Xbox gaming console. (PS1.0 was never used)
DirectX 8.1
Most Notable New Feature: Pixel Shader 1.2, 1.3, and 1.4 where pixel shaders can use up to 28 instructions at a time. Pixel Shader 1.4 was only utilized by the ATI Radeon 8500.
DirectX 9.0 Shader Model 2.0
Most Notable New Feature: More powerful pixel/vertex shaders thanks to Shader Model 2.0. Shader Model 2.0 supports a pixel shader length of up to 96 instructions. Also adds improvements to DirectPlay and several improvements to audio and video.
DirectX 9.0 Pixel Shader 2.0b
Most Notable New Feature: Used first on the ATI Radeon X600/700/800 series of GPUs. Pixel shader 2.0b supports more instructions (up to 1,536) and more temporary registers (32 versus 12). As well as a new facing register. 2.0b also supports geometry instancing.
DirectX 9.0 Shader Model 3.0
Most Notable New Feature: Shader Model 3.0 where pixel/vertex shaders support more instructions. Shader Model 3.0 also supports flow control/dynamic branching, which allows developers to add loops to their shaders, making programming easier. Used first on the NVIDIA GeForce 6800 series of GPUs.
Dx8 is not good(efficent) nowdays, i think lfs dont use any shaders which means its not using the most powerful part of the cards. DX10 uses unified shaders so it makes more faster/efficent than dx9 cards. I got nvidia 7600GT card which is old now but lfs always run at 80-100+fps(1680*1050 Full) -> time for a new engine
Btw i think we have to wait for a new graphics engine until S3, more people will buy it + the bigest "problem" is the new engine could let us night driving etc so the old dx8 cant stay longer(compatibility).
+ dx8 in 2009 is lol. He could hire a programmer for this.
Sry for my english.