My current setup is: 2009 20" nvidia iMac, 4GB RAM/640 GB HD I generally would like to know what my expectations for decent video playback should be - thankful for any help people can offer on this: When using the Apple DVD player on full-screen mode, dvd playback seems quite grainy, with pixel lag on fast video sequences. Specifically, I was watching original DVD music concerts. The concerts were at night, so the picture is darker, but on my TV & stand-alone DVD player, the picture was less grainy and there was no 'pixel lag'. During computer playback no other programs were open, WLAN was off. The HD is empty except for Apple's stock software. So, could one or more of the following be a logical reason for grainy playback?: a) it's a computer, not a stand-alone DVD player hooked up to a TV. b) screen quality: TN panel compared to CRT TV. c) integrated graphics, i.e.: the 2008 iMac with dedicated ATI Radeon 2600 Pro card would be smoother. d) display settings on Apple's DVD player. (using stock settings BTW) e) full-screen mode performance is generally not perfect on any system. f) none of these - something else entirely.