When did Vcore change to VID? (It didn't!!)

EarthDog · Aug 22, 2014

Ok people, this is killing my OCD nature... :chair:

VID = Voltage Identification (stock voltage)
Vcore = The voltage the CPU is currently using

Vcore can be VID, VID cannot be vcore unless the Vcore value is the same as the VID(stock voltage).

I have seen lately, over the past several months, people using VID as vcore. For example, I adjusted my VID to 1.35v. As I understand it, VID is the stock voltage of a given CPU. It is a STATIC VALUE on one chip but can be different on each chip as each chip's stock voltage is different.

To me though, VID cannot be the term used for anything outside of its stock voltage.So, when the heck did this change suddenly occur? I see this all over forums and am wondering if I missed the memo that VID is all of a sudden interchangeable with Vcore. Set me straight please or perhaps set those straight that are not using it right? :shrug:

Mr.Scott · Aug 22, 2014

or perhaps set those straight that are not using it right?

This.^^^

You're correct my friend.

Silver_Pharaoh · Aug 22, 2014

I always thought VID is the Vcore the CPU wants, while Vcore is what it gets. :shrug:

Johan45 · Aug 22, 2014

You're right E_D, your spidey senses were tingling for a reason. It's not the only term that gets misused either.

ATMINSIDE · Aug 22, 2014

Silver_Pharaoh said:
I always thought VID is the Vcore the CPU wants, while Vcore is what it gets.

EarthDog said:
or perhaps set those straight that are not using it right?

Go EarthDog, it had been driving me up the wall as well.

EarthDog · Aug 22, 2014

Silver_Pharaoh said:
I always thought VID is the Vcore the CPU wants, while Vcore is what it gets.

That is, surprisingly, closer than the reason I posted at least!

... one have to consider vdroop and such...

But yes, VRM sends a voltage to the vid portion of the CPU, the VID says I need X and the VRM supplies it. Which after that it seems to then 'turn into a VRM supplying that voltage to the rest of the silicon.

Wiki has a good read - http://en.wikipedia.org/wiki/Voltage_Identification_Digital

The correct supply voltage is communicated by the microprocessor to the VRM at startup via a number of bits called VID (voltage identification). In particular, the VRM initially provides a standard supply voltage to the VID logic, which is the part of the processor whose only aim is to then send the VID to the VRM. When the VRM has received the VID identifying the required supply voltage, it starts acting as a voltage regulator, providing the required constant voltage supply to the processor.

Instead of having a power supply unit generate some fixed voltage, the CPU uses a small set of digital signals, the VID lines, to instruct an on-board power converter of the desired voltage level. The switch-mode buck converter then adjusts its output accordingly. The flexibility so obtained makes it possible to use the same power supply unit for CPUs with somewhat different nominal supply voltages and to reduce power consumption during idle periods by lowering the supply voltage.[4]

Bobnova · Aug 22, 2014

VID switched from parallel pullup/pulldown resistors on a set of pins in the socket to a serial transmission over a couple pins in the socket at LGA1155, if I recall correctly.
That's why you can VID mod the LGA775 stuff, you are literally modding the VID pins.
That makes the CPU request a different vcore.

Bobnova · Aug 22, 2014

Gave this some more thought.
Here's the super super simple version, from the CPU's point of view:

VID = Voltage I (the CPU, NOT you the user/bios) Demand.

Vcore = Voltage I Got.

VID is a theoretical request number. Like requesting a PB&J sandwich, with jelly made from blackberries harvested from bushes grown in the shade only near but not actually under redwood trues and bread made from non-GMO wheat.

Vcore is a physical voltage, it's the sandwich you actually got. It may or may not resemble the sandwich you ordered.

You the end user do not get to touch VID. Ever.
It's the CPU's request.

Silver_Pharaoh · Aug 22, 2014

So I was half right? :shrug:

freeagent · Aug 22, 2014

Thank you ED, this has been an annoyance to me for the last while too.

Straight from the horses mouth..

When did Vcore change to VID? (It didn't!!)

EarthDog

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Mr.Scott

Beamed Me Up!

Silver_Pharaoh

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Johan45

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ATMINSIDE

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EarthDog

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Bobnova

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Bobnova

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Silver_Pharaoh

Likes the big ones n00b Member

freeagent

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