[Rayce185]

So in my pursuit to find out why I can't set the VTT on my XFX 780i over 1.4V (highest available), I was told by tech support that "if the option is not available then this voltage is not supported on this CPU / board configuration".

This is new to me.

I have tried both my Q9550 and a E5200 on this mainboard, and both show a max FSB voltage of 1.4V. Of course it may be a coincidence, but I strongly disbelieve that the CPU alters the BIOS' settings to disable the use of higher voltages. I mean, I also have the ability to set the Vcore to 1.8V, so it's not like capping the VTT at 1.4V (if that's the case) is protecting the system from over voltage.

What is your take on this?

 

[madmike0408]

I have never heard of this before, I've never used that board but I haven't ever heard of anyone else saying this. The overall limit of the motherboard is probably 1.4V.

 

[PERSPOLIS]

The tech support is talking nonesense!Voltages are normally limited by the motherboard,not the cpu!
That said, I'm surprised.Your mobo should support higher vtt.

 

[Conley]

I thought motherboards were the only thing to limit voltage.

 

[R00ST3R]

Isn't 1.4v Vtt dangerous? For a 45nm chip at least?

 

[PERSPOLIS]

Quote:

Originally Posted by R00ST3R Isn't 1.4v Vtt dangerous? For a 45nm chip at least?

NO,but some say 1.4v is the max safe vtt for 45 nm chips!

 

[Rayce185]

I was on the EVGA forum. They say that some version of the BIOS update started limiting the VTT to 1.4V. Now it's my turn to find out which one =/

Aaaaand what compatibility issues I may have. Not that I go down to P05 and then my Q9550 isn#t supported anymore

Good thing I have two spare CPU's lying around for backup (until they get the same IHS treatment and be smoked)

 

[systemaxd]

To add my $0.02 to this topic on voltages particularly CPU FSB (VTT) on my board, and it should be almost identical electrically (minus vdroop control) with my chip e6600 i have the VTT voltage selection from 1.200v up to 1.725v and running according to cpu-z if i read it rite P06 bios.

I have the evga 780i FTW version will update my rig specs.

 

[Rayce185]

Do you have the standard EVGA 780i SLI, or the 780i SLI FTW?

 

[supaspoon]

My xfx 780 capped at 1.4 as well, and the actual values would be .02 below bios setting (1.3 = 1.28 etc.).

What kind of fsb are you going for? I ran my 9650 on it at 475 (1.39vcore) w/ vtt at 1.28v(1.3bios).

Regardless of that, this board starts getting tricky at/above that anyway. Have you dialed in your gtl values? That will most certainly help.

 

[Rayce185]

Interesting:

I have upped my Vcore to 1.45 (I have vdroop) and it runs stable at 475MHz, but I had to abort Linx after about a minute due to heat, the CPU was going at over 80°C...

I need to get this TEC installed...