# What is the difference between CPU NB VID and NB Voltage?



## Artas1984 (May 4, 2012)

1) NB Voltage Control
2) CPU NB VID Control

What is the difference? I know one thing - i must increase both the north bridge frequency and voltage in order to overclock a Phenom II, but i don't get it which setting is actual the north bridge voltage control and what is the other?


----------



## lilhasselhoffer (May 4, 2012)

What is VID: http://www.overclock.net/t/251112/cpu-vid

Short: start-up voltage


How do I overclock a Phenom (idiot's guide): http://forums.guru3d.com/showthread.php?t=267708


The short of it; don't change VID.  The other setting is what you want to play with.


----------



## repman244 (May 4, 2012)

NB Voltage control is for the NB that is on the motherboard - you don't need to change that, it will likely cause more problems than good.

CPUNB - the NB that is in the CPU (memory controller), the safe voltage is somewhere up to 1.3V but I run it around 1.25V for 2600MHz. Remember that on Phenom II CPU's in order to get maximum performance from overclocking you also need to overclock the CPUNB (most people only overclock the CPU but forget about the NB).
One thing you need to be careful with CPUNB is that it depends on the CPU clock, so for example:
If you have your CPU at 3.5-3.6GHz, you should have the CPU_NB at around 2600MHz, running it at 2800MHz could give you less performance.


----------



## Artas1984 (May 4, 2012)

repman244 said:


> NB Voltage control is for the NB that is on the motherboard - you don't need to change that, it will likely cause more problems than good.



Looks like you were right, not the first replier.


----------



## lilhasselhoffer (May 4, 2012)

Artas1984 said:


> Looks like you were right, not the first replier.



What?


Read the second article, please.  

You mess with CPU voltage, frequency, and multipliers first.  Once everything is stable there you need to slightly bump up the NB voltage.  Messing with the VID increases the initial voltage to the North Bridge, which shouldn't need to happen unless you're pushing some crazy memory overclocks.

If you're starting with the NB then you've got some priority problems.  Perhaps a bit more background would help?


----------



## Athlon2K15 (May 4, 2012)

different motherboard and cpus will respond to the CPU/NB voltage differently,for instance my crosshair formula 3 only needed 1.17 for 2800 and 1.24 for 3000


----------



## Artas1984 (May 5, 2012)

lilhasselhoffer said:


> What is VID: http://www.overclock.net/t/251112/cpu-vid
> 
> Short: start-up voltage
> 
> ...



Well... Increasing vid voltage allowed to boot Windows when CPU was overclocked. Keeping it to default did not allowed me to boot... Both of you guys state different opinions... Although i agree with athlonx2 from experience that motherboard means a lot...

*Also i don't need the idiots guide*.. I have had experience ocing AMD CPU since NF4 times, i only need a specific part about the difference between what i mentioned...


----------

