GT240 1GB here, with an old CRT monitor on the left and a DFP on the right.
CRT resolution=1024x768, DFP res=1680x1050, using Twinview.
Composite enabled + Kwin effects.
I'm on a light load right now: some browser windows in different virtual desktops, a text editor, nvidia settings app, Konsole open with 2 tabs, etc.
Temp is at 61ºC, performance level=2 (maximum), adaptive.
Room temp ~30ºC, since outside is 28ºC (typical Spanish mediterranean weather).
I only reach 8XºC temperatures on full load (playing a 3D game in fullscreen, etc).
Previously I had a laptop with an Nvidia card always at 8XºC (idle). It died a year later. Twice. Warranty expired. Probably an Nvidia bugged card. No refund.