A XDA forum member has released his HD2 overclock tool allowing you to overclock to 998Mhz (apparently it really is underclocked as standard) on battery or up to 1200Mhz when plugged in!

Seems to give a nice little boost!

Check it out here http://forum.xda-developers.com/showthread.php?t=682663

it only works while being charged after it goes back down to orginal and whats the point factory set speed is more than enough

No it is not. It scale to full 998 as it is supposed to. I'm quite certain that FPSEce makes it go all up (998). About overclocking, I never tryed it so tell us how much improvement it is at 1200.
Well I still really recomend you this software and disable autoscaling of processors frequency. Some normal thing that normaly doesnt inform processor that it should go all up will be much quicker. The most significant change I observed is keyboard. It now response really accurately and is great for typing.

but not a single extra-fps on tekken 3 or need for Speed for me.....

i900frenchaddict: And what settings you runned? Overclocked?

Not really, it seems that is goes back to 998mhz when fpsece is running (even if my HD2 is plugged) so it changes nothing for me, fpsece already usually stresses the CPU to 998mhz...
Maybe my rom (radio version?) is too old to handle going over 998mhz correctly (but I keep this old rom because I never had the "y auto lining up" thing)

I would be curious to know if people here can go over 1000mhz while fpsece is running and thus can see a significant boost in fps on games that are not full speed (tekken 3, Diablo, NFS....)