Turbo? Speedstep? i7 920 OC questions

Here's the rundown, been running Prime95 for an hour. The temperatures were the max of any of the 4 cores for both idle and full load. I made sure to have HT on and 8 threads going in Prime95. First of all, I'm pretty sure my temps are alright, but if they aren't that's my biggest concern, I need this computer to last more than 6 months.

i7 920 @ 3.6 (D0)
Mugen 2 (AS5)
Asus P6T Deluxe V2
OCZ Platinum 1600 @ 7-7-7-20 - 1440
BLCK - 180 x 20
Vcore - 1.2
QPI/DRAM - 1.2

Max. Core Temps:
100% load - 63c
Idle - 40c
Ambient - 21c (70f)

My ram isn't running at 1600, and SpeedStep and Turbo are off. Should these be of any concern to me since it seems to run pretty stable (fast too)? I've read that SpeedStep and Turbo on a mild overclock can achieve some impressive results. Saving power doesn't seem like a bad thing to me either.

If anyone out there has any advice at all for my setup, please let me know! I'm hoping I can change the ram speed independently from the BLCK and that if I do push the ram to 1600 that turning on SpeedStep or Turbo wouldn't have disastrous effects on the system.

Thanks in advance!

Thanks for the quick reply. I went ahead and tried turning LLC off, didn't change anything else at all. I went from an hour stable to immediate prime95 crash. Turned it back on and all is well for another hour.

How do I change the ram multiplier? I assume it's in the AITweaker section somewhere.

I'm using Core Temp and giving the MAX temperature that any of the 4 sees over the course of the run. I'm not sure where people get the CPU temp that is a couple degrees lower than their core average. I'm all for information so if there is a program that measures something differently I'd definitely try it out.