CPU VID vs CPU Core Voltage AMD 880 Chipset

[storm-chaser]

I've learned that VID is what is set in the BIOS and Core voltage is ACTUAL voltage getting to my CPU.

However, why is my board (Biostar a880GZ) showing a higher core voltage than VID? You would think due to vdroop it would be the opposite.



and

 

[Mr.Scott]

VID is what the CPU calls for, not what you set in the bios.

 

[EarthDog]

VID is what the CPU calls for, not what you set in the bios.

This.

In another thread I recall Bovnova saying to think about it as Voltage I Demand (where I is the processor). Its just the programmed values on the CPU for stock/given multiplier. Vcore is the actual voltage.

Also vdroop is the difference between idle voltage and load, not bios to windows. What you are describing I call vdrop (one o).

 

[storm-chaser]

VID is what the CPU calls for, not what you set in the bios.

So if I go to custom P states in the BIOS I have the option to change the core VID, in example:



And if we look in AIDA64, the VID change is reflected here:

 

[EarthDog]

Truth, as you confirmed, yes.

 

[storm-chaser]

Truth, as you confirmed, yes.

So are we all in agreement that VID can, in fact, be set from BIOS, as described in post #1 or am I missing something here?

 

[freeagent]

So are we all in agreement that VID can, in fact, be set from BIOS, as described in post #1 or am I missing something here?

You cant change that on older boards and cpu's, so no, the vid is still embedded in the cpu and is read by the mobo. It is a pre determined voltage range as set out by intel and programmed into the cpu so the mobo knows what kind of voltage to feed it at what clock speed, ie stock+turbo. I am not current on anything passed 3rd gen i7, so.. that's where my knowledge and guesstimation ends.

 

[Mr.Scott]

So are we all in agreement that VID can, in fact, be set from BIOS, as described in post #1 or am I missing something here?

On some new boards, yes.

On old boards sometimes you could pin/pad mod them, but for the most part, no, it is embedded in the CPU.

 

[storm-chaser]

You cant change that on older boards and cpu's, so no, the vid is still embedded in the cpu and is read by the mobo. It is a pre determined voltage range as set out by intel and programmed into the cpu so the mobo knows what kind of voltage to feed it at what clock speed, ie stock+turbo. I am not current on anything passed 3rd gen i7, so.. that's where my knowledge and guesstimation ends.

Okay this makes sense, but I'm talking specifically with my hardware configuration (chipset, motherboard, CPU etc), it appears the VID value can be modified ( as laid out in post #4) from the pre programmed value using custom P-states. And that change is reflected in AIDA64 under the VID value. With this specific motherboard (Biostar A880GZ) there is no other place in the BIOS to specify voltage.

 

[Mr.Scott]

It is just the way they named the function. They're calling vcore VID. That's all. There are a few manufacturers that use slightly different terminology.

 

[storm-chaser]

Okay, good deal. Last question. Can anyone explain why my actual voltage at the CPU is higher than what's set in the BIOS?

You would think due to vdrop the processor would reflect a lower voltage value in CPU-z, but in fact the opposite is true.

Is this just a software discrepancy?

 

[Mr.Scott]

Nope. Board probably just overvolts a little. Very common.

 

[EarthDog]

Okay, good deal. Last question. Can anyone explain why my actual voltage at the CPU is higher than what's set in the BIOS?

You would think due to vdrop the processor would reflect a lower voltage value in CPU-z, but in fact the opposite is true.

Is this just a software discrepancy?

I do not know the reason why. Vdrop doesn't always exist. There could be none, or as I call it, vRaise. I've seen it on plenty of boards as well. But more so on older boards/CPUs.