MikeB on 06 May 2010
@ NightAntilli
As an example, you can't say the HD4870 is weaker or has less power than an HD5450 because the lack of DX11 in the 4870 while the HD5450 does have that feature.
It is not weaker due to a lack of DX11 support. It's easy to imagine a much stronger GPU lacking DirectX 11 support and it's also easy to imagine a weaker GPU with DirectX 11 support.
DirectX 11 is just a Microsoft API.