Multi GPU vram issue

[sydjy]

Hello everyone !

 

First of all, excuse me for my english, it's not my native language 

 

I have a very tricky probleme that you guys gonna enjoy think on :

 

 

My actual configuration :

 

cpu : i7 920

mobo : p6t se (old 1366 socket)

GPUs : SLI gtx580

RAM : crucial 3*4g (trial channel)

SSD : corsair 120go

on Windows 7 x64

 

I currently have 2 display, my main ACER 1080@120hz, and a spare normal 1680*1050 display.

 

 

I wanted to add a 3rd monitor (not for surround or gaming, juste a normal display for video/browser).

 

I know that with the 580 series, i can't run more than 2 display with SLI enabled (i don't want surround), so i brough a GT 730 just for the the accessory display.

 

THE PROBLEM:

 

I don't know why, but the OS copy in the gt730 the same data in VRAM than my 580, even if there is nothing connected to that gt730 !

 

For exemple : i use to run a TERA (an online game), with only the 580's on the PC, like i always did, everything is fin (With or without SLI enabled)

 

But if i just connect the GT730 to the motherboard (with no monitor connected to it, no 3rd display connected or whatever else), it copy all the game data on the gt730 VRAM too, and of course that cause the game to run like shit due to the low speed/capacity of vram.

 

Why the OS send that to the gt730 too ? I tried enabling/disabling SLI on the 580, tried various combo of video output on the 580's, but it's always the same.

 

Screens in idle on windows7 : ( image in attach files)

 

 

 

As you can see, there is data on the 730's VRAM without even a display connected to it ! (Like i said, it happen with game data too)

 

 

How do I make this gt730 to run by itself without slowing down my 580sli ?

 

I hope someone has the answer to this because i'm driving nuts  :wacko:

 

 

Thank you very much !

 

 

 

[Tedster]

Welcome to the Forum. Your English seems fine.

This is fun.

I have absolutely no idea how to fix this.

[sydjy]

Thank you for you answer !

 

 

Yeah i don't get it, i just tested something, even with only the 2 gtx580 on the mobo, SLI DISABLED, the 2nd 580 get the same data on VRAM as the 1st.. without even being connected to a display. 

 

I must have missed something  :huh:

 

If someone have a clue, feel free to ask me to try think, i'm out of ideas at this point.

 

Just want the 580's to run in SLI on the main monitor while the 730 just power up the 2 accessory display, without having the in-game performance completely destroyed by the "mirrored VRAM data" on the 730..