I installed a new NVidia Geforce GTX 550 TI today and ran some more tests. With the AMD card installed, the processor utilization was around 60% with hardware acceleration enabled or disabled. With the new NVidia card, the processor utilization decreased from around 60% to around 20% with hardware acceleration enabled. With hardware acceleration disabled, the processor utilization increased back to 60%. This leads me to believe that hardware acceleration on AMD cards (DXVA2) is not compatible with MadVR. NVidia uses CUDIV which is compatible with MadVR. My conclusion is that if you want to use hardware acceleration, get an NVidia card. In my system, I am running a low power Sandy Bridge Pentium so offloading video decoding to the video card frees up lots of CPU cycles. If I was running a high performance processor, it wouldn't matter as much.