I have an unusual problem. I render a frame and it takes 1:46. Seven frames later it takes 2:18 to render a frame. Fifteen frames later it takes 2:34. After a few hours of rendering it takes over 5 minutes to render a frame. I am using Blender 2.79b with an Acer Predator G1-710 Intel i7-7700 3.6 GHz Nvidia GeForce GTX 1080 and Windows 10 64 bit. My animation is about 17,000 frames long and I use hair and particles and transparencies. I have set Cycles render using the GPU. I am rendering single layers. The workaround is for me to close Blender, re-open it and continue rendering where I left off. The render time for the next frame is then 1:56. I do not have this problem rendering the same file on my Mac nor on my old PC. So, does anyone have any ideas as to how I can achieve a relatively consistent render time for each frame?