How can I reach -0.065 offset on vCore?

[Premudriy]

Hello to everyone,

My system is Rampage IV Extreme + 3930K + G.Skill 1866 16GB (4 sticks) + NH-D14 cooler. I aim to stay at 4.3GHz.

I have read in another post that some people (Toddd240) are reaching -0.065 vCore offset voltage. I don't know what is wrong with my settings, but my system is unstable even if I go below -0.010 vCore offset. Another person (Conard) says that he could achieve this with no LLC. If I set LLC to Disabled/Regular, then I can't do negative offset at all.

Here are my BIOS settings. I have offset at -0.020 right now, but it definitely crashes in Prime 95 and also sometimes crashes by itself, so it's not stable at all. Please see if there's something definitely wrong with my settings.


//========================================================
My current BIOS is v3101:
Ai Overclock Tuner: Manual
CPU Level Up: Disabled
BCLK Frequency: 100.00
CPU Strap Auto:
ClockGen Full Reset: Enabled
Turbo Ratio: By All Cores, 43
CPU Clock Gen Filter: Auto
Memory Frequency: 1866 (native freq. and timings)
Xtreme Tweaking: Enabled
EPU Power Saving Mode: Disabled

CPU Vcore: offset, -0.020 (for now)
VTT CPU Voltage: 1.10000
2ndVTTCPU Voltage: Auto
VCCSA: Manual, 1.100
DRAM Voltage: all set to 1.5 volts (native ram voltage)
CPU PLL Voltage: 1.78125
PCH 1.1v Voltage: Auto
CPU Spread Spectrum: Disabled
PCIE Spread Spectrum: Disabled

DIGI+ Section:
CPU Load-line Calibration: Medium
CPU Current Capability: Auto
CPU Voltage Frequency: Auto
VRM Over Temperature Protection: Auto
CPU Power Duty Contro: T.Probe
Vcore MOS volt. Control: Auto
CPU Power Phase Control: Standard
CPU Spread Spectrum: Disabled
CPU VCORE Boot Up Voltage: Auto

VCCSA Load-line Calibration: Regular
VCCSA Current Capability: 110%
VCCSA Fixed Frequency: 300
CPU VCCSA Boot Up Voltage: Auto

CPU VTT Switching Freq: Auto
CPU VTT Over-Current Protection: Enabled

DRAM-AB Current Capability: 110%
DRAM-AB Voltage Frequency: Auto
DRAM-AB Power Phase Control: Optimized
DRAM-CD Current Capability: 110%
DRAM-CD Voltage Frequency: Auto
DRAM-CD Power Phase Control: Optimized

PCH 1.1V Switching Freq: Auto

CPU Configuration Section:
Intel Adaptive Thermal Monitor: Enabled
Hyper-threading: Enabled
Active Processor Cores: All
Limit CPUID Maximum: Disabled
Execute Disable Bit: Enabled
Hardware Prefetcher: Enabled
Adjacent Cache Line Prefetch: Enabled
DCU Streamer Prefetcher: Enabled
DCU IP Prefetcher: Enabled
Intel Virtualization Tech: Enabled

CPU Power Management Configuration Section:
CPU Ratio: Auto
Enhanced Intel SpeedStep Tech: Enabled
Turbo Mode: Enabled
CPU C1E: Auto
CPU C3 Report: Enabled
CPU C6 Report: Enabled
CPU C7 Report: Enabled
//========================================================

[Nodens]

Just because someone else did, it doesn't mean you can as well. Each chip is different. With LLC disabled, negative offsets will most likely crash you on idle if you go too low..very hard to believe someone did -0.065 with Regular LLC unless the UEFI version he was using was setting a very high default vcore for his chip to begin with plus using underclocking or very close to stock with a chip that could also take undervolting. You see there are just too many factors involved. Don't try to mimick what others do, just find the lower voltage your own chip can take and stay there:)

EDIT: Imho work out the lowest voltage your chip can take at Regular or Medium.

[Arne_Saknussemm]

Aiming for a fixed OC or voltage value is never going to work unless by pure coincidence. Every CPU is different. As Nodens said find what works for you....... and "believe only half of what you see and nothing of what you hear" goes triple for the internet.

[Premudriy]

Thank you very much, guys, for your help. So how about those other voltages like VTT, VCCSA, PLL? Are they fine like that for 24/7 or should I be lowering them?

[Arne_Saknussemm]

Yes, they are all fine. You can always tweak for lower voltages if your system allows after finding the key stable Vcore. Try the minimum negative offset of 0.005 and if this is not stable try positive.

PLL can in many cases be lowered to about 1.6 but you would have to test this. I have VCCSA and VTT at 1.05 but again this is something you have to test.....but the values you have are A-OK! 🙂

[Premudriy]

Thanks, Arne! So the PLL/VTT/VCCSA voltages you mention are for the speed that you have in your signature, i.e. the 4.6GHz?

[Arne_Saknussemm]

Hehe yes but don't take that as a recipe for your system. What works on mine may not be the best for yours. In fact a lot of people can't run negative offset above 4.4GHZ for example. I just let you know these values so you have a rough idea. The first thing you have to figure is your Vcore and then play with the others.

[Premudriy]

I see, great! I'll start from scratch and set other voltages to their default/intel specs and figure my best, minimal, stable vCore offset first.

Thanks again to everyone for the help. I really enjoy these ROG forums due to one of the friendliest atmosphere out there.

[Premudriy]

Hey, guys, I just came back to leave feedback on my re-overclock.

I can't believe this. Basically what really fixed it is actually lowering the PLL voltage, seriously. After some messing around I just dropped the PLL to 1.6 (like Arne has) and now my offset is -0.040 and Prime 95 stable. I'd never guess that lower PLL will actually make things more stable.

[Arne_Saknussemm]

OCing can be a strange world...is your system stable at idle too? no dropouts at lowest voltage ? Anyway it just goes to show that each system is unique and you have to find what's right for yours. Kudos for experimenting! Glad you're off and running!:D