I'm not sure if this is the right place to post this, if you think it should be moved, please do so.
At home I have two computers:
1) Toshiba L505-12Q laptop, with an Intel Core2Duo T6600 processor (2.2GHz,2MB L2 Cache, 800MHz FSB), 4GB RAM DD3@1066MHz, ATI Mobility Radeon HD4650 with 1GB dedicated DDR3 RAM and a 5400rpm 500GB Sata2 hard disk. Laptop's monitor has a maximum resolution of 1366x768 pixels and there is also and HDMI out which I use to connect it to a 40'' Samsung TV (FullHD) to watch movies.
2) A custom made desktop pc with a Core2Duo E6300 (2M Cache, 1.86 GHz, 1066 MHz FSB), 2GB RAM DDR2@667MHz, ATI Radeon HD5570 with 1GB DDR3 RAM and a 7200rpm 250 SATA2 hard disk (WD). Desktop's monitor is a LG 22'' FullHD connected via DVI.
I have PCLinuxOS KDE installed on both computers (using the latest 2012.08 images), updated and using the proprietary Catalyst drivers (configured through PCC). Desktop has no problem playing EVERY HD video I put on it, out of the box, no matter the size or the resolution. Laptop cannot play 1080p videos no matter what I've tried so far. I have tried several videos (mostly 1080p movie trailers) with various players (mplayer, VLC, XBMC) and many options for each one of them, following numerous tips and tutorials across the net. In general the problem is with the video being too slow or not playing at all and the audio being ok. 720p videos mostly play without problems on all players.
I'm close to the conclusion that it's my slow hard disk to blame. I just wanted to have some feedback from ATI users around the forum so maybe I could come up to something I haven't tried so far. Maybe run some tests to verify the speed of the laptop's hard disk?
Any help would be greatly appreciated. If someone wants, I can give more info about my system or what I've tried so far and failed.
Thanks in advance!