CPU Voltage Jumping & Slightly Different from BIOS

[Collider]

I'm testing OC settings for X5670 and one concern I have is the CPU Voltage differs slightly from my BIOS settings when I check it in Windows using CPU-Z, HWMonitor or OpenHardwareMonitor.

The difference isn't much, its +/- 0.003
+0.003 under 100% load with Prime95
-0.003 when idle

For example, my BIOS setting is v1.325, and in Windows when idle it shows as 1.322, when under 100% load its 1.328

The board I'm using is Asus P6T Deluxe V2 and Corsair 850W PSU - so I know both are solid.

I also have all power saving features & SpeedStep disabled in BIOS. Load Line Calibration (LLC / VDroop) is enabled. CPU Spread Spectrum is enabled as well.

Could this be a sensor reporting issue in Windows or should I be concerned? Or this due to one of my BIOS settings?

 

[lopri]

Nothing whatsoever to worry about. That is a tiny variance which could occur among motherboards came out of the same conveyor belt. Plus, these software readings are ballpark figures to begin with. Only way to measure true vcore is doing it old-school, using a multimeter. Usually there are several vcore measure points on a given board, and the measured values will vary depending on other factors (e.g. distance from the socket). BIOS nevertheless attempts to report a value, and in Windows software simply relay that value to the GUI. From my experience, those values are often lower on consumer-oriented motherboards than what are actually measured, which is not surprising.

TL/DR: You are already dealing with an approximation. A slight variation of it does not warrant an alarm.

 

[Burpo]

Also, Speedstep needs to be on to achieve maximum turbo for a single core.

 

[Collider]

Nothing whatsoever to worry about. That is a tiny variance which could occur among motherboards came out of the same conveyor belt. Plus, these software readings are ballpark figures to begin with. Only way to measure true vcore is doing it old-school, using a multimeter. Usually there are several vcore measure points on a given board, and the measured values will vary depending on other factors (e.g. distance from the socket). BIOS nevertheless attempts to report a value, and in Windows software simply relay that value to the GUI. From my experience, those values are often lower on consumer-oriented motherboards than what are actually measured, which is not surprising.

TL/DR: You are already dealing with an approximation. A slight variation of it does not warrant an alarm.

Thanks for explaining. That puts my mind at ease.

Sent from my XT1575 using Tapatalk

 

[Collider]

Also, Speedstep needs to be on to achieve maximum turbo for a single core.

Even when overclocking? I always thought that adds to instability of the OC?

Sent from my XT1575 using Tapatalk

 

[ClockHound]

Even when overclocking? I always thought that adds to instability of the OC?

Sent from my XT1575 using Tapatalk

Only if you're going for an eXtreme OC. 4.1 Ghz on the 5670 is safe to use with Turbo. My 5675 runs at 4.4 and turbos to 4.6(ish). Downhill on a windy day. Still doesn't pull more than 1.36V in Turbo using offset voltage.

If you were to run it at 4.6+ and cranking more than 1.4V then turbo could push it into instability. But the temps would probably limit you before turbo did. Unless you have one of those new open-sided cases that can fit icepacks.

 

[Collider]

Only if you're going for an eXtreme OC. 4.1 Ghz on the 5670 is safe to use with Turbo. My 5675 runs at 4.4 and turbos to 4.6(ish). Downhill on a windy day. Still doesn't pull more than 1.36V in Turbo using offset voltage.

So at the moment I'm at 200 x 21, 4.2 Ghz with 1.3125 VCORE.

How do I figure out how high it will Turbo up to? I have 22 & 24 Multi's available (no 23), but with 24 thats 4.8 Ghz which sounds a bit high (I couldn't boot at 4.4 Ghz with 1.325v).

Also is there a way to control what the Turbo Multiplier and Voltage offset will be?

 

[Burpo]

With speedstep enabled you will see 23 & 24 Multi's when there's not much load. No, as said earlier, your board has no offset (adaptive voltage settings).

 

[Collider]

With speedstep enabled you will see 23 & 24 Multi's when there's not much load. No, as said earlier, your board has no offset (adaptive voltage settings).

Thanks for clarifying.