The ps3 can output in many different modes but our TV;s cant handle most.
A standard NTSC tv reads 480 to 5225 lines of video so the res is in that range.
A simple way to find the best res for your tv is after you boot and login type:
xx corasponding toCode:ps3videomode -v XXbut for most tvs 480i is the only thing that will work. You can also have it out put in dither, by adding 2048 to the ID or -d to ps3videomod, or Full screen by adding 128 or -f.Code:0: auto mode , default value YUV 60Hz 1:480i 2:480p 3:720p 4:1080i 5:1080p YUV 50Hz 6:576i 7:576p 8:720p 9:1080i 10:1080p RGB 60Hz 33:480i 34:480p 35:720p 36:1080i 37:1080p RGB 50Hz 38:576i 39:576p 40:720p 41:1080i 42:1080p VESA 11:WXGA 12:SXGA 13:WUXGA
HDTV's are capable of reaching higher res. If you type something in that makes your screen blank trust yourself to hit the up arrow and delete the last number (press delete once, you wont see anything but it will be working) and then press a working number, such as 1, and then enter.
Most American NTSC tv's are 60Hz so 50Hz screen modes with results in a scrolling effect.