AMD Radeon HD 7750 & Radeon HD 7770 GHz Edition Review: Evading The Price/Performance Curveby Ryan Smith & Ganesh T S on February 15, 2012 12:01 AM EST
Video Post-Processing: GPU Loading
We saw in our coverage of discrete HTPC GPUs last year that noise reduction loaded up the GPU, and as such, was even disabled in the low end GPUs for want of shader resources. Starting with this review, we are planning to tabulate GPU usage under various post processing scenarios instead of running decoder benchmarks. GPU-Z gives us the necessary data for this purpose.
A 1080i60 H.264 clip (same as the one used in the discrete HTPC GPU article last year) was decoded with the LAV Video Decoder (DXVA2 Copy-Back mode) using EVR-CP as a renderer in GraphStudio Next's Decoder Performance section. Various post-processing options were turned on and off in CCC and the GPU usage recorded in each case.
|Video Post Processing GPU Usage: 1080i60 H.264|
|AMD Radeon HD 7750 (1GB GDDR5) / Catalyst 12.1|
|LAV Video Decoder DXVA2 (Copy-Back) v0.46 / EVR-CP|
|Post Processing Algorithm||GPU Load|
|No Video Post Processing||19%|
|Vector Adaptive Deinterlacing + Pulldown Detection||25%|
|Dynamic Contrast and Colour||25%|
|All Post Processing / 'Enforce Smooth Video Playback' Disabled||62%|
We also put some Full SBS / Full TAB 3D clips (which are basically 2 x HD resolution) through the same process. Those progressive clips resulted in around 70% of the GPU being loaded with all the post processing steps enabled.
It is not yet possible to use the madVR renderer from within GraphStudio Next, but, in future HTPC / HTPC GPU reviews, you can expect to find similar benchmarking with the madVR renderer (now that it is possible to use madVR along with hardware accelerated decode for AMD GPUs also). That said, we see that up to 62% of the GPU is loaded using just EVR-CP. It is not clear how much room is left for madVR processing, and we hope to address that question in future reviews.