Patrice,
I've got 92 processes = 1425 threads running concurrently with ObjReader. I run a hellofalot of desktop gadgets (ca. 5% CPU power) and a few semi-transparent sliding dockbars (another 4% CPU power) for my tools and apps. ObjReader proper was consuming only
5.1% CPU the moment I took the topmost screenshot below. Regarding GPU consumption, we're on a par with each other when the animated bubble ship is made to rotate at its default zoom on scene load.

And ObjReader proper was consuming around 26% CPU when I took the bottommost full-screen shot with the model zoomed in decently to occupy the entire unobscured viewport.

It's like heaven and hell compared to my former GTX 650Ti readings, which in their turn were not so bad at all compared to cheaper office-style video cards. And my GPU's temperature at full screen is now ca. 38
oC only at 30% fan speed.
(not a sound in the room whatsoever!
)