Thought I might chime in here with all those iMac 5K problem threads going. My base i5/290 model with 512GB SSD and 16GB RAM, title says it all, runs silent and cool and has a perfect screen with no yellowing or backlight bleed. When running my Trainz Simulator game for hours on end, or when ripping a DVD in Handbrake, fan speed never rises above the default inaudible 1200RPM, while GPU temperature stays below 60 degrees C. I'm glad I swapped my nMP + Dell UP2414Q for this beauty. I'm also glad I withstood the temptation to go for the i7/295 combo. Have fun!