Should I believe BIOS or CPUZ/Sandra?

hey all, new rig arrived yesterday (specs in sig) and im having a little trouble getting it prime stable @ 301*9(2709MHz).. Ive uped the volts in BIOS to 1.5V, but in CPUz/Sandra its reporting the VCore as 1.472.. if i set in bios 1.475 it shows up on CPUz as 1.45.. should I go with what CPUz is telling me, and then raise the volts till it says 1.5 in CPUz, or should I go with what BIOS tells me and that its already 1.5?.. its a shame, i can boot, burn in, play games etc etc fine, not a problem at all, but when it comes to prime95/super pi, it fails almost instantly temps load are 34/35 (cpu/case) any suggestions?

Careface*

They read the value from the same place, so I don't think it makes a whole lot of difference. The voltage will fluctuate, esepcially if your PSU isn't up to the task. Some boards undervolt and some boards overvolt, so you need to consider that as well. Set it in BIOS, save reboots and go back into BIOS, see how much over/under it is, and correct it accordingly. If it fluctuates too wildly, you may need a new PSU.

As douglas said, some boards overvolt and some undervolt, it's just the nature of the beast. For me, my BIOS reading (not what I set it at) and CPU-Z readings are the same. Go into your BIOS and go to "PC Health Status" or something like that and it will give you temps and voltages. See what it says in there and then check the CPU-Z reading. Either your board undervolts slightly or your PSU is having a rough time keeping up with the load.