I'm working with an i7 860 and a Gigabyte GA-P55M-UD2. The build in my sig is correct except I've added a Cooler Master Hyper 212+ and an extra 1TB Seagate LP, mostly for backups.
I've been doing lots of tweaking lately in BIOS and decided to start playing with speed and voltage. My initial goal is to see what I can do at stock V (although to learn how the V settings worked I actually undervolted) and with HT, Turbo, EIST and sleep states enabled. My overclock and undervolt are very small steps right now. I've been doing a lot of reading and think I'm taking the right steps. But I thought it'd be a good idea to get some feedback.
On the Advanced CPU Core Features page I enabled everything. Turbo, EIST, C1E, C3/C6/C7 Support, etc.
I left my CPU clock ratio at 21, QPI clock ratio at Auto, and PCI Express Frequency (MHz) at Auto.
I changed BCLK to 145.
In the Advanced Voltage Settings, I set:
CPU Vcore = Normal
Dynamic Vcore (DVID) = -0.01250 (as I said a minor undervolt)
DRAM Voltage = 1.5V
I have tested at with Prime95. According to CPU-Z I am getting the following:
Idle: x9 Multiplier, ~1.197 GHz, 0.848 V Core Voltage
8 threads: x22 Multiplier, ~3.190 GHz, 1.120 V Core Voltage
1 Thread: x26 Multiplier, ~3.768 GHz, 1.216 V Core Voltage
How am I doing? Anything I should be doing differently? Is CPU-Z an accurate way to measure the Voltage? Is there a better way?
I also changed the other settings on the Advanced Voltage Settings. They were at Auto. I set them all to Normal. Should I just set actual values for them? They include:
Ch-A Data VRef.
Ch-B Data VRef.
Ch-A Address VRef.
Ch-B Address VRef.
Is there a way to measure these other voltages, such as Vtt, PLL, PCH?
You are doing very well so far, and that is an excellent chip there. But raising the vcore is only going to get you so far. I dont know about the 860, but with the 920 you need to start raising the ioh and ich once you reach a speed of about 4.2-4.4 ghz.
Keep raising the vcore until you need to raise it dramatically to get a small performance increase, or you reach dangerous levels. Then start raising the vtt and the qpi voltages together and that should help you overcome those walls.
in any case CPU-Z should provide an accurate voltage, and so should your BIOS status in the BIOS menu.
Thanks for confirming. My BIOS shows Vcore and DRAM in two different screens - the MB Intelligent Tweaker (M.I.T.) page and the PC Health Status page. And the values are never the same! But they're always within about ~.03 V of each other so to be safe I tend to assume the higher number is correct. Most of my testing relies on CPU-Z anyway.
Thanks everyone for the responses. Overshocked, that is a helpful link. That has the more detailed explanation I was looking for. I tend to steer away from the guides that say raise this or that without saying why because I like to learn what the settings I'm tweaking actually do. So I appreciate that level of detail.
It seems like in some ways the P55 simplifies things. Of course every architecture decision has trade-offs too. But with more work being done on die there's no NB & SB anymore so the IOH and ICH are replaced by the single PCH. The QPI as it exists on the 1366 disappears too. As I understand the architecture, it is still used internally on the CPUs to connect the PCI Express controller to the CPU Cores. Which would explain why in my BIOS I have a single setting labeled "QPI/Vtt Voltage", whereas with Bloomfield they were separate settings that controlled different things.