I just received my 2.8 Octo with 4 GB RAM, HD2600 and am starting to notice some VERY poor performance. First off, video playback is choppy at best, otherwise it doesn't play at all. I've tried Quicktime with Flip4Mac and Perian, and also VLC. All formats, WMV, AVI, MOV, MKV, etc. HD, SD, resolution or bitrate doesn't matter. It just stutters, if it plays at all. The VLC error that comes up says, "more than 5 seconds of late video -> dropping frame (computer too slow ?)" I don't understand, a brand-new 8-core mac pro "too slow?" The whole time the processors aren't above 2% load and I have 3 GBs of free RAM. Transfer speeds over Firewire 400 and abysmal as well. I'm getting read and write speeds ~2-20 MB/sec, never over 20. That's not normal, right? Also, I unRar'd a 900MB archive and it took about 15 minutes. It doesn't even seem like these problems could be related. I'm upgrading from a Pentium M 1.8GHZ Windows laptop, and it was faster at every one of these tasks! Can anyone shed some light on what's going on here?