My system information:
Operating System - Windows 10 (64 bit)
CPU - i7-5930K @ 3.50GHz
RAM - 32GB DDR4 (4x8GB)
GPU - AMD R9 Fury X
Storage - PCI-e SSD OCZ Revodrive (500 MB/s writes, 900 MB/s reads)
Radeon Software Version - 16.9.1
Blender version - 2.78 (Date installed: 2016-09-26)
No add-ons or other things installed with it.
Things I've done to try and remedy this issue:
- Increased Memory Cache Limit to 20GB under User Preferences > System > Sequencer/Clip Editor.
- Changed Compute Device to my GPU, switched to Cycles Render engine, and setting Render > Device as GPU Compute.
- Setting OpenSubdiv compute to GLSL Compute and Images Draw Method to GLSL.
- Using the new DepsGraph by adding
--enable-new-depsgraph
to blender's launch shortcut. - Setting Threads under Render > Performance to 10.
- Disabling OpenGL Preview under Scene Preview/Render.
- Setting the preview properties Proxy Size to 25% and making the preview window smaller.
- Setting Preview Samples under Render > Sampling > Samples to 1 (minimum).
All I'm trying to do is use Blender as a video editor. I'm not doing any 3D modeling or animation. Whenever I am previewing an effect, even if I let it cache fully, my FPS drops to 5 or less, and blender is almost unresponsive until the effect is no longer being previewed. CPU usage jumps to around 70-80%. It would only jump to around 20-30% at times before I started using the new DepsGraph.
At any other time, when just video and audio are being played (no effects, animations, or otherwise), I get a constant 30 FPS. Even if I run the preview at the scene's render resolution (so 1440p), and set Preview Samples to 0 (unlimited), I get 30 FPS.
The clips I'm handling are 2560x1440 resolution running at 30 FPS that were encoded to HEVC (x265) at a bit rate of 2500 Kb/s. The entire project is only 7 minutes and 13 seconds long (12990 frames). Even if I limit the playback segment using P, it still essentially locks up when previewing effects. The entire clip I'm editing is 228MB in size.
I'm using 3 effects. A crossfade transition, a wipe transition, and a speed control effect. All at different times, and any of them causes this behavior immediately once they start.
This may be entirely unrelated, but I'm unsure:
Before I switched to the new DepsGraph, if I set OpenGL Render Options > Anti-Aliasing on, all previews hit 14 FPS maximum. If I change said Anti-Aliasing's Samples to 5, 8, 11, or 16 (those are the options it gives), the average FPS does not change (it's around 13).
After switching to the new DepsGraph, this is no longer true. I get 30 FPS until I hit the Effects I mentioned above.
I've researched and tested things for a while from various forums, as well as reading questions asked on this stack exchange. I'm at a loss for why I'm experiencing these issues.