Why use "Above VID %"?

[lex89]

What is the point of using this option? Why wouldn't one just set the CPU VID to the exact number they want?

[tristancarton]

some people need more voltage than what the maximum is. regular max on my nf3 is 1.55. with the extra above vid % you can go much higher. you also able to get many inbetweens with these percentages.

[Autochthon]

I use it so I can OC with RMclock

[dmo580]

I think he's wondering like

 

You can get 1.400 from 1.400 * 100%

 

Or you could do...

 

1.275 * 110% = 1.4025

 

or I use 1.35 * 104% = 1.404

 

THey'r epretty much 1.4 volts but whats the difference? Why not just set 1.400 * 100%

[mack73]

I was talking with an old electrical engineer about this and I can't remember the exact terminology he described. So I'll probably look like a dumbass, but it was something to the effect of voltage verses current.

 

Voltage would be the amount supplied, then you need to take the current into consideration. Under load, to compensate for the increased power requirements, the current will be increased to keep the volatage steady

 

So I beleive the voltage is the CPU value and the special is the percent the current can supply extra?

 

Not sure exactly, so this is probably all wrong :shake:

[evogre3n]

I was talking with an old electrical engineer about this and I can't remember the exact terminology he described. So I'll probably look like a dumbass, but it was something to the effect of voltage verses current.

 

Voltage would be the amount supplied, then you need to take the current into consideration. Under load, to compensate for the increased power requirements, the current will be increased to keep the volatage steady

 

So I beleive the voltage is the CPU value and the special is the percent the current can supply extra?

 

Not sure exactly, so this is probably all wrong :shake:

 

what? :eek2: lol

[mack73]

Since I had no idea with the difference between voltage and current is, here's an anology I found:

 

A simple analogy likens voltage to the pressure of water in a

pipe. Current is likened to the amount of water (charge)

flowing per unit time.

 

 

But does this apply to this situation, I have no idea

[Guest Shibby]

So this is only for water-cooled systems? What does the flow have to with your cpu voltage, temperature or something?

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

hahah, just kidding. Just funny seeing you try to explain it

[Autochthon]

voltage is how high, current is how big. watts is how squashed you are when big falls from high

[shira]

My understanding is that some OC'ers find that they get better results using a lower CPU VID combined with a non-zero Above VID % than they get when specifying CPU VID and 0% Above VID %, even when the total Vcore is the same for both methods.

 

It makes no sense, but apparently it's a real effect for many.

[Guest Spartacus]

My understanding is that some OC'ers find that they get better results using a lower CPU VID combined with a non-zero Above VID % than they get when specifying CPU VID and 0% Above VID %, even when the total Vcore is the same for both methods.

 

It makes no sense, but apparently it's a real effect for many.

 

 

I've heard this too and wondered why that would be. The only thing I can think of is kind of a load balancing effect. Kind of like if they are two different voltage sources being added together. The load is not as high on the primary circuit when you use the "Above VID %" secondary circuit. It may all be happening in the same programable voltage regulator chip, but it still may be separate circuits within that chip. We'd have to find out from Oskar if that analogy makes sense or not compared to the actual circuit design.

 

The water pipe analogy for voltage and current is pretty good.

 

voltage = the water pressure (PSI) in the pipe

current = the amount of water in gallons

power = how much work you get from it (like turning a water wheel)

 

When you OC your computer, you are using more current while the voltages are staying relatively the same. The equation is voltage x current = power (watts). That's why you need a high wattage PSU for a serious OC rig. You need more current to get more work (watts) done. The voltage is a constant and not really relevant.

 

This is why it makes no sense when people say their 300W PSU has great voltage readings in their OC rig and it must not be the reason it keeps crashing.

 

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