Gpu Rendering vs Cpu Rendering , which one is more efficient ?

Hey All ,
I am Poznan / Poland based Architect / 3D Environment Artist , with passion for 3D modelling , rendering since my early bachelor period it means nearly 6-7 years , In this article rather than giving a lot of technical knowledge I will try to share with you my recent GPU (Graphics processing unit) rendering experiments and compare it with my old CPU (Central processing unit) rendering works ( I recently started to render with GPU before around 1 month I was using CPU rendering ).

Firstly I had to choose right and compatible hardware for my computer to use GPU rendering because as you know most of GPU render engines such as Octane , Redshift , Fstorm are only supporting rendering with Cuda Chipset Graphic card so after long time of researching (around 6 months in spare times ) I have finally decided my computer set up for GPU rendering . Actually I wanted to set up the computer which will be working good also for few more years so I didn't hesitate to invest more to get better hardwares such as i9 7920x and Nvidia Geforce 1080 ti , and also choosed motherboard which support 4 Graphic cards for future extensions.It was hard and rough period of time while deciding all computer parts and putting them all together to work but It was nice experience and worth all exertions.

Finally when I had all my set up working , then I could start to have fisrt experiences with GPU rendering but there was another question now . which softwares I would choose fot it , It was also not so easy to choose but , I would say was easier than choosing hardwares so I have finally decided to use Maya / Redshift (even I was influenced a lot by the render quality and speed from Octane render ) because I was Maya software user as main 3D package and It was hard for me to swith C4D for using octane so I choosed redshift as renderer because It has made firstly for Maya so It could be implemented better inside Maya ( Its only my point of view).

Then I have started my first GPU rendering experimental work "Shadow of the Purple Night " , It is little bit blade runner inspired work as I am influenced a lot from movie , I wanted to experiment realistic materials and Volume lights in night time. I used Maya for All modelling , Substance Painter for Texturing and finally Redshift Render engine for rendering all frames and Animation , Render quality was very satisfying for me , for frames I have setted up 1080HD frames and for animation 540p frames so generally for one frame renderes render time was around 5 minutes , and for animation frames were around 1minute so it was sufficient time to complete animations with my set up. As comparing with CPU rendering Before I was experiencing to render one frame in same quality (1080HD) with maximum optimal options were like around 15-20 minutes at least , so according to my experiments GPU rendering were working at least 5 times faster and is possible to reach same quality with that speed.

I am also sharing results of my GPU rendering experiments . Cheers.

Animation links : https://www.instagram.com/p/BcNNi1CgKUJ/?hl=en
https://www.instagram.com/p/BddjgLMAW0l/?hl=en