EDIUS 11 supports GPU hardware acceleration for preview and timeline export:

Acceleration for preview

From 11.10.13684, EDIUS suppports H.264 (AVC) and H.265 (HEVC) hardware decoding with NVIDIA NVDEC. Also if your PC has both supported NVIDIA GPU and Intel Quick Sync Video, GPU is selectable for acceleration.
GPU acceleration also works during previewing the timeline that some video filters applied. 

Acceleration for export

From 11.11.14359, selected GPU accelertion works for rendering some video filters. If your PC has both supported NVIDIA GPU and Intel Quick Sync Video, GPU is selectable for acceleration.
NOTE: This function does not work on remote rendering.

Steps to enable GPU hardware acceleration

Applicable video filters
GPU acceleration works for below video filters (both preview and export)

– Primary Color Correction
– Monotone
– Median

Procedure
For decoding H.264 (AVC) and H.265 (HEVC) file

1) Select Settings > System Settings > Importer / Exporter > AVCHD / HEVC.

2) Tick ‘Use Hardware decoder’ option.

3) Click [Apply] > [OK].

For preview and export

1) Select Settings > System Settings > Hardware > Video Rendering & Playback.

2) Tick ‘Use GPU’ option. If necessary, select the GPU that you want to use from the drop down list.

3) Click [Apply] > [OK].

System requirement

Requires Intel, NVIDIA or AMD GPU supports Direct3D Feature Level 11_1 or upper. You can identify supported feature level by running DXDIAG tool. Type dxdiag in search box and go to [Drivers] tab then see appeared feature level in Driver pane.