iMac - high or low density ram

i have been looking up so much info on these 2 and i cant seem to find a strait answer. I have the g4 800 imac, and im not sure which is the correct 144 pin ram to use. I have 1 of each (one has 4 chips on each side, and the other has 8 on each side). I have searched and searched the interenet (i dont have the manual) so i cant find the suggested configuration. I had a Micron 512 pc 133 low density chip in there and after about an hour of basic use, my dock and application run time seemed to really bog down. So now im testing the high density (yes it recognizes all of the memory). Any info would be great! The inside already was installed with a 512 168 pin, so i can max out to 1 gig, but i just want to find which is the best way to go. thankyou!
-dave-