Help wanted:

I use an old MOTU 1224 with a new PC (2,8 Ghz - 1Gigabyte Ram - P4P800 Motherboard and Intel 865PE Chipset -Raid System), Logic 5.5., and windows 2000.
Sometimes Logic runs fine (20 Tracks with a lot of effects) but most of the time I get the Logic Error: ASIO: Disc is too slow or system overload (-10010) and I cannot playback longer than a couple of seconds.
I tried all different settings in the Logic Audio Driver window and in the MOTU console but no changes.
I'm a beginner with all this computer stuff and happy about every hint.