Long story short. This is my testrender with 5 samples on fullHD 50% and it took 13 mins on CPU as GPU couldn’t handle it.
And when i read others had 5 hours of rendertime i decided this is a very good time to test BlenderGuru’s Grass Essential Pack, what i bought for myself for christmas
This is done in fullHD with 20000 Bahia grass and some dandelion and needle grass, with 512 samples on GPU in 23 minutes!
I know it was mentioned that this texture based grass-particle system is not the best way to do it and i know we had to learn this technic. I just wanted to show what is possible, i hope you like it.