good glad it was something simple. 36C at full load is great. ok intel uses something called speedstep it automatically downclocks the multiplier when it is idle. you can turn this off in the bios and sometimes it helps give a higher oc with the trade being power consumption. if you oc with it on then it will still down clock but at the new ratio you are running your oc.
turbo is something intel uses to give you a boost on single threaded applications. you can set your computer to run on turbo always and it will give you the extra multiplier by enabling performance mode in windows. you also need to turn off c-states in bios to do this. so 19 is what you get all the time that way, the reason why you see 21 sometimes is when a single thread only is running turbo can boost it up that high. (its diferent for the differant chips and I dont have yours info in front of me so I am assuming its 19 and 21 as you said.) I think the only way you can run 21 constantly is if you disable 2 or 3 of your cores, which sorta defeats the purpose of an sr-2 IMHO.
you seem to be fairly new to overclocking in general. read and comprehend this guide here: http://www.evga.com/forums/tm.aspx?high=&m=583817&mpage=1#583817
most of the gulftown stuff aplies but its mainly principals you need to understand so that you can ask specific questions about your sr-2.
there is a wealth of information here in the sr-2 section if you browse back over the last 2 years, especially the posts from early 2011.
good luck, and post if you have more questions. if you have general oc questions like the ones above you will probably get more people looking to help if you post in the overclocking section, but keep in mind if you ask something sr-2 related most of those members will try to help but may give you wrong info due to the quirkiness of the sr-2. I have seen so many people try to answer questions about the sr-2 having never even owned one, lol. but what do I know, lol im just another guy with a 4.5ghz oc on my sr2 lol. definantly not an expert.
forgot your first question, lol. the intel chip itself will shutdown when it goes nuclear, but this is unavisable. there isnt a setting in the bios, but you can download a program like coretemp which is free and you can set to do it. there are other free and paid for programs that will do this as well as certain fan controlers.
<message edited by Gratuitous on Tuesday, July 31, 2012 8:15 PM>
“I built a castle in the swamp and it sunk. I built a second castle and it sunk too. I built a third castle and it burned down and then sunk. But the fourth castle, Ahhhh! That one stood.”
—Monty Python and the Holy Grail