What's the difference between VTT and VID?

[mellojoe]

I know VID is the core voltage. But what the heck does VTT do? (in layman's terms)

 

[PliotronX]

It is the termination for the CPU's FSB interface, sometimes labeled in motherboard BIOS as vFSB. It can help with stability at high FSB with quads in particular. JFYI the consensus for 24/7 maximum VTT with 45nm chips is about 1.45v and 65nm chips 1.5v. Any higher could degrade CPU life noticeably (i.e. before we at the [H]ard Forum normally replace our CPU's ).

 

[graysky]

VID isn't the really the core voltage. CPU Vcc is technically what that's called. My DFI board incorrectly refers to the processor vcore (CPU Vcc) as VID though.

As PliotronX said, VTT is the FSB termination voltage (also called reference voltage). He is right to warn you about those levels for 45 and 65nm chips. I wouldn't exceed 1.40 V (real) for a 45 nm chip.

 

[mellojoe]

Yeah, I'm using a DFI motherboard.

I haven't touched VTT. Its sitting at the stock setting of 1.0v.

When would I need to up the VTT setting?

 

[BinarySynapse]

VID isn't the really the core voltage. CPU Vcc is technically what that's called. My DFI board incorrectly refers to the processor vcore (CPU Vcc) as VID though.

As PliotronX said, VTT is the FSB termination voltage (also called reference voltage). He is right to warn you about those levels for 45 and 65nm chips. I wouldn't exceed 1.40 V (real) for a 45 nm chip.

VID is what the voltage regulator uses to set Vcc for the CPU right?

 

[Down8]

When would I need to up the VTT setting?

He answered before you asked.

... It can help with stability at high FSB with quads in particular. ...