I just got my new mac pro set up and Photoshop CS3 running. My question is how high can I/should I set the memory usage in prefs? I know that PS can only use about 3.7GB total and that anything above that will be used for scratch before turning to a hard drive. Since I have 8GB, it seems like it makes sense to set it to 100% as there is plenty of overhead for the system but I'm not sure if that would be optimal. Can't seem to find a good answer with Google. Thoughts?