The default voltage in BIOS for my Xeon X3220(G0) (Q6600 equivalent) is 1.26V( I cannot decrease below this value) but HWmonitor or CPU-Z shows 1.15V in iddle and 1.12V in full load. I saw on the internet printscreens with CPU-Z showing 1.15V for Xeon X3220 so this is not happening only for me.
The CPU is able to pass Intel Burn Test at 3ghz(333x9) with default voltages.
For 3.2 Ghz ( 400 x 8 ) I need to set 1.3V from BIOS but the voltages shown by HWmonitor and CPU-Z are 1.25-1.26V in iddle and 1.22-1.23V in full load.
The temperatures are also very weird. At 3.2Ghz I have 40-45 degrees Celsius(CPUTIN) in iddle and 50-55 in full load. In Intel Burn Test the max temperature was 61C and 57C in prime95(run for almost 9 hours). The cores temperature must be higher but everytime the shown temperature for the cores is 5 degrees lower.Is it possible to have a lower temperatures on the cores or the Xeons are a little weird?
My OC e5200 had 35C in iddle and 60-62 in Intel Burn Test and the cores were always 5-6 degrees hotter.
My motherboard is an Abit IP35P, the Power supply is an Antec TruepowerTrio 550w and the cooler is Zalman CNPS 9900 LED
It is possible that the voltage monitor on the board is not working right. More likely the board employs some kind of power savings feature. Newer gigabyte boards(P45 UD3L) under volt the Q6600 G0 as well.
The drop from idle to load is normal and is called vdroop. My Q6600 G0 would droop to 1.168. This was not enough for 3.2 so i did a mod to the board to stop(greatly reduce) the droop.
See if you have an option called load line calibration. If its there, turn it on to minimize the load voltage drop.
Some boards require Speed Step and C1E to be turned off before changing voltages. This will take away power saving features of the cpu and increase idle temps a bit.
On a side note 1.12 @ 3.0 is impressive for that cpu. Remember that as you raise the voltage, the temps will climb faster and faster(Power consumption also jumps fairly fast after 3.0-3.2).
So the readings for the cores temperature are wrong?
You mean they are supposed to be hotter than the CPU.
Idle temperature at 3.2 400x8 is around 40C and 50-55 in full load and Zalman CNPS 9900 LED is a great cooler. I had higher expectations from Xeon G0
Going higher can be done. You need plenty of voltage(and cooling to match) and its best to have a vdroop mod or option to prevent it.
Many extreme overclocks you see are very good chips(all chips are different) with water cooling. That being said, My Q6600 G0 "Could" get to 3.6 ,but with temps hitting the 70's it was just too hot for me. I had settled on 3.2 on stock voltage(with a vdroop mod, so my vcore was higher then the 1.68 it used to get).
How is your case ventilation. I do not think 55 was a bad temperature to be honest. If you want to lowest idles, make sure Speed Step and C1E is on and set the computer power scheme to portable/laptop(For XP, Vista and 7 should default to the right settings). You can edit the sleep times and whatnot, just leave the drop down setting at portable/laptop.
Also be aware that your board seems to have 3 power phases(look next to the cpu socket), so it may be harder on the system pushing very high clocks as those phases each work harder then say a board with 8 phases.