Has the title explains I experience some very low performances with only two HD layers using the Add50 blending. I did the benchmark and I have this :
1 layer 35 fps

2 layers 19 fps

3 layer 13 fps...
All my files are in DXV. Here's my config:
nvidia 970GTX with latest driver.
Intel i7-3770 at 3.40 Ghz
DDR3 16 Gb
My computer is very clean (I use it for video editing) and I'm experiencing the same problems on a good gaming laptop of a friend.
Help please !