So I chose this completely silent graphics card. This is simply what is best in CG silent (with the model of Sapphire too).
In terms of games: with 8GB of RAM and a amd FX-6300, I run starcraft 2 up to the maximum, same for diablo 3, Left4Dead 2, Tomb Raider (a hair below the max), crysis 3, call of duty etc.
In this config, I reach the 35 FPS, so it may seem slight, but it speaks of a silent configuration ...
It can be put in crossfire and get almost double performance!
At temperature, at full load, the graphics card goes up to 75 ° C, and is generally between 60 and 70 ° C. At rest, 40 ° C (it depends also if your case is broken, how fan etc., I have an input fan 800 rpm, and an output 800 rpm, so the vital minimum).
For those who prefer to sacrifice the quiet side, I advise for the same price and more efficient:
R7 250X or HD 7790.