I recently got a 24" external monitor. It has been a real revelation for my photography hobby, (and it's pretty cool for watching DVDs too) I am noticing some performance lags in some circumstances and I'd appreciate your expertise on whether this is an issue with processor, RAM or graphics card (or something else) I have the 2.33Ghz Core2Duo 2Gb RAM model, so it's far from shoddy. Aperture When working in Aperture I usually have the image full size on the big monitor, and then the control panel, browser and any other apps I need on my laptop monitor. When I make image adjustments (e.g. exposure, cropping, tilt) there is quite a lag between moving the slider and seeing the result on screen. This is especially annoying when trying to tilt an image to the horizontal, because it is quite fiddly work. Without the external monitor there is still a perceptible pause but not enough to complain about. With it, it is a little frustrating. System monitor I've been keeping an eye on my RAM usage and although I sometimes get very low on inactive RAM I always have at least around 20% of the pie as free (or the other way around, I mix them up ) Question I will probably upgrade my MBP at the next major apple upgrade. Any thoughts about what is the limiting factor here? Or am I just expecting too much?