Confused About Odd Readings From Monitor Tools For i5 2500k Overclock

[General Techniq]

I've overclocked an i5 2500k cpu to 4.0ghz, heading for a goal @4.5ghz. However, I immediately became confused by the readings I was receiving from monitoring tools @4.0ghz.
I've circled some of the puzzling readings with blue marks in the pic below:

Details:
-I'm completely confused by the vcore readings in CPUz (my initial tool) and CPUID-HW
-The max temps in Core Temp are freaking me out (98C). They occur in very short split-second spikes straight from the regular max temps (60ish) at random and infrequently.
-Previously, Real Temp refused to display anything for my cpu clock, cpu load and multiplyer other than all zeros (0000). It would only show my core temps and that "Distance to TJMAX" stuff. Now, ALL OF A SUDDEN, it wants to start working.... I didn't change anything other than using the FPU stress test instead of the Blend Test this time around.
-What worries me most is that Core Temp is the only one that seems to monitor my Vcore correctly, which makes me feel that I should pay serious business to those insane core temp spikes it keeps logging.
-I've disabled the C-states and C1E in the bios

SPECS:
-Core i5 2500k
-Z68MA-D2H-B3
-EVGA GTX 570 HD
-Corsair Vengeance 8gb (2-sticks) Dual-Channel DDR3-1600 CL9 Memory
-Antec High Current Gamer 900w PSU (80+ Bronze)
-HAF 912 case with 6 fans installed
-Hyper 212+ with 2 fans (push/pull)
-500gb Barracuda (something) SataIII HDD
-Generic Cheap DVDR-RW drive
-Somewhat decent wire management
-Artic Silver 5 on the CPU/HS


What's up with these readings?
I have a feeling I should be worried about something, but don't know what that something is.

 

[jsc]

First of all, different temperature monitoring programs calculate temps a little differently. You will notice that RealTemp and CoreTemp readings agree. Obviously, CoreTemps 98 C max reading is wrong. The CPU would have thermally throttled itself.

Second, you are confused about VID and core voltage. VID is the voltage that the CPU will program the power regulator on the motherboard to produce. It is fixed by hard wiring in the CPU. However, the motherboard can adjust that voltage to a certain extent in response to CPU load factors.

Third, system voltage readings in Hardware Monitor: HW frequently gives out and out wrong voltages. Obviously, the 12 volt reading is not 5.04 volts. If it were, the system would not boot. And many programs cannot accurately calculate negative voltages.

I use RealTemp and CPU-Z. They indicate that your system is running fine and that you have more than 10 C of headroom before you bump into Intel's recommended max temps.

The readings indicate that your system is running fine with the settings you have.

 

[General Techniq]

Thanks for the helpful reply, jsc. It was very informative (and a bit embarassing on my part).

So, I'm assuming that the CPU core voltage was really 1.056v @ 4.0gHz full load with that 10c headroom on the temp, and that I could simply set the multiplier a bit higher (from 40x to 43x) without any serious danger?

I'm wanting to eventually reach 4.7+ gHz on the CPU, if a can, in order to aid in running a second gtx570 that I'll be getting in a few weeks for sli. However, If I can, for example, reach 4.5gHz without having to manually tinker with the voltage settings, I'd be just fine with that.

 

[jsc]

Well ...
Intel's recommended max voltage for 65 mn Core2's: 1.50 volts.
Intel's recommended max voltage for 45 mn Core2's: 1.45 volts.
Intel's recommended max voltage for 32 mn SB: 1.52 volts.

But I do not think that I would run an SB CPU much past 1.40 volts. Your 1.056v @ 4.0gHz full load seems to indicate that that you won a CPU lottery.

It's been my experience overclocking Core2 CPU's that with a quad, you are going to bump into thermal limits before you reach the voltage limits unless you have a CPU with an unusually high VID.

You do have a little more room to pust the OC a little farther. At any rate, I do not think that a SB CPU running at 4 GHz is going to bottleneck a pair of GTX570's.

 

[General Techniq]

I'm glad to hear that about the GTX570's. If that's the case, then I guess I can settle for a 4.2 ghz clock to keep the temps reasonable until I can explore a better cooling solution.

Thanks again for the help.

 

[General Techniq]

Best answer selected by General Techniq.