i7 950 newbie overclock questions

Hi guys,

so I finally decided it was about time to o.c. my system :) So far so good, I'm testing it now. It's not a huge overclock (I run on air cooling, aftermarket one), I increased bus speed to 160 Mhz, and set multi to 23 getting 3.68 Ghz. I'm using a core voltage of 1.272 (by default at 3.2 turbo was 1.25, 1.232 with default 3.07 not turbo). Ram settings were unchanged since I can run them at their previous speed of 1600 MHz, on an XMP profile (DRAM volt is 1.65 and QPI volt at 1.4). Turbo and HT off. Now...:

• is there a way I can let the sytem decrease my Core voltage, like it did before, when the CPU is at idle? Now it changes the multiplier only.
  
• QPI link frequency was 3200 MHz according to CPU-z. If I left it at auto it went down to 2890. Other option is 3520 MHz, or higher. What should I do?
  

Are there any other particular settings I should be aware of? Core temperature is around 75-76° on core 0, 72-73° on cores 1 and 2, 70° on the 4th. I use Coretemp to monitor, but I see Real temp says about the same.

By the way, my mobo is an ASUS Sabertooth X58.

Thanks for your help

Fede

Edit: Those temperatures are with Prime95 running, not idle!! :)