As far as i know the latter model xscales dont overclock as well as the older ones. my c3000 hits 624Mhz easily and i had a x30 that could do just under 700Mhz (on both you would notice the heat), i asume from your join date that you have one of the newer models
basically the only problem with overclocking is the extra heat generated and the extra current draw (a 50% increse dosent mean 50% extra power). for example. my x30 at full load at 624Mhz (betaplayer 1.5Mbps xvid) would get just above 40mins of usage
if you want to do it i recomend you dont do it in hot areas. dont go above 624Mhz unless you need that sort of power and are plugged into a wall (you really shouldnt need that much power) and you stress test your Z
some are better than others and can work at a slightly lower core voltage at a given freq. compared to other cores. i am unsure of how it is done in pdaXrom but the kernel support generally has these values hardwired into the kernel (ie you cant fiddle with them) which is a shame because if you are willing to set up some automated testing you can net yourself some extra battery life
also i recomend some sort of dynamic cpufreq scalling. this will knock the cpu up to a higher value when you need it and down when you dont. i use to run the ting at less than 100Mhz for decoding MP3's because of the extra battery life it would give me
for the trulley insane i recomend removing the RF shield and installing a mini heatsink jaycar has perfect sized ones that i use to cool 2 ixp425 xscales that do a good job however you could fit somthing a bit bigger in if you want to do a case mod (stop giving me ideas)
for info on how to remove tho RF shielding see the hardware fourms, specifically the bluetooth posts and vist alberters site (currently down) for the multipliers and registers for overclocking i recomend the xcpuscaller fourms (windows CE but they do talk about which multipliers give the best performance) and the intel manual
hope it helps but was probbelly not what you were after
