Here's my specs: 2011 Early MBP 15" Anti-Glare HiRes Display 2.3Ghz Quad Core i7 (Sandy Bridge) 16GB RAM (Crucial) 256GB Samsung 830 SSD (SATAIII) 23" Aluminium Cinema Display (via TB to DVI) Apple Aluminium keyboard Logitech wireless mouse I use this laptop as a desktop all the time nowadays and just unplug the cables if I am on the go and just stuff the laptop in my bag. My question is, when I have it in clamshell mode, it just seems a bit "laggy" than when I have it open as a laptop. My question is, why does it feel sluggish when in clamshell mode? The fans are always running high (which is a known issue with the MBPs). Why doesn't it feel like a "desktop"? The processor is plenty fast, the SSD is there, RAM is adequate. What am I missing? I highly doubt the AMD GPU is having issues at 1920x1200. Anyone else have similar experiences? I mean I have a Mac Pro and it always works smoothly, no lag. It's a 2008 Quad Core.