I've done some tests and i'm sharing them hoping they are useful. I can't share the blend file as is internal work from my job. I have another old machine of the same specs but i could't make it work with CR yet. I repeated the test with the gpu at the end to take into account the balance between machines that CR calculated from the previous renders.
Crowdrender version 0.13 pre-release.
Single frame render.
f12 means rendered only in the main machine.
cr means rendered with the Crowdrender button.
When rendered in CR i've made 3 renders in a row to take into account the balance calculations.
Render time in seconds.
f12 gpu 212x216 - 40.71
cr gpu 212x216 - 49.74 - 44.14 - 42.92
f12 gpu 32x32 - 1:26.06
cr gpu 32x32 - 1:24.39 - 1.20.64 - 1.17.67
f12 cpu 32x32 - 1:21.44
cr cpu 32x32 - 1:18.14 - 1:17.88 - 1:17.68
f12 gpu 212x216 - 40.81
cr gpu 212x216 - 43.68 - 42.85 - 41.63
CPU Intel core i5-4460, 3.20GHz 4 cores (no hyper threading)
RAM 8GB DDR3
GPU Nvidia Quadro K620, 384 CUDA cores, Driver 376.33
Blender 2.79 with CR add-on
CPU Intel Core 2 6400, 2.13GHz 2 cores (no hyper threading)
RAM 2GB DDR3, 8GB swap on a disk HDD
GPU GForce 7300 GT (no CUDA compatible, not used for rendering)
Manjaro Linux 7.1.3 (last version rolling release)
Blender 2.79 with CR in the terminal as instructed in this post: https://www.crowd-render.com/forum-1/general-questions/crowdrender-headless-comand-on-slave-computers
The slave machine is quite old and for now it's not enough to reduce render times in comparison with just the main machine gpu. Maybe if i get the second one working i'll get lower render times :-)