i would hope that temp is wrong or its about to explode... does it burn you just holding it?
Its a bug in Speccy, reported a year ago - see here:
http://forum.piriform.com/?showtopic=41575
try :
http://www.almico.com/speedfan.php (it picks up more censors than are normally attached so some will be real high, you can ignore them) I wouldn't use it to run fans but its a handy temp monitor
Its not even close to being right, if gpu hit 511c wouldn't the motherboard be a tad warmer than the 28c it currently is? Laptop would shut itself down.