Like in 3ds max, DirectX is the priority API in Autodesk AutoCAD. Moreover, the newer versions of this CAD application do not even have a standard OpenGL driver. Nvidia, on its part, offers a special AutoCAD Performance Driver (previously known as PowerDraft) that features hardware support for software Gooch shaders necessary to render technical images. Thanks to that, the driver accelerates performance by up to 500% (according to Nvidia). The test results confirm this.
Even the junior model of the Nvidia Quadro FX series is capable of delivering higher performance than the senior representative of the ATI FirePro series. This is due to the excellent optimization of Nvidia’s drivers for Hidden and Conceptual rendering modes in which invisible edges are hidden in models. In the other two modes, Wireframe and Realistic, the performance of the cards from AMD and Nvidia is proportional to their pricing.