i need your help i have a piece of shit amd e-2 1800 in my toshiba satallite c855-d....
what is the highest i should overclock it to???
(it normally runs at 1.7 gHz at 523 MHz(680 MHz in Turbo Core))
Zilch. The cooling is bare adequate to run stock operation, not to mention power may not be able to accommodate an OC anyway. Of course, that's assuming you can even overclock. Typically, OCing is locked on a BIOS level on most every laptop.
Bottom line: It's highly impractical, if not impossible to overclock on a laptop, especially with low-power CPUs.
^Agreed with jerm, obviously.
Most laptops are very difficult to overclock. If you do manage to do it, it's only by like 100-200mhz..(in my experience with acer laptops).. It's not worth it.
There are options for you though. I'm not saying that you should, but you could resell that laptop and purchase a better PC. I've sold a couple of my APU laptops months ago and they sell fairly quick.