I stumbled over this article http://www.lowendmac.com/practical/02/0507.html Maybe this is of help for some of us. Anecdotal notes: I remember for anything other than simple word procession OS 9.2.2 in Classic mode under Tiger on an ibook 2005 with 1,33GHz had stuttering mouse cursor movement. So maybe this does help. I didn't try it myself though, since I have Macs that can natively boot into OS 9 that I use instead, if I need OS 9. (Interestingly 9.1 under 10.2.8 runs fluently in Classic mode on an iMac G3 DV, its interesting that it runs weaker on the faster ibook).