Multiple Displays on 3-Way SLI GTX 465's

[awmcgee]

I am having problems getting all my displays to work.

I have 3 total. Two HP 23" LCD's (VGA and HDMI ports for options) and one Vizio 3DTV. I am running three GTX 465's (2 EVGA, 1 Galaxy) in a 3-way SLI configuration on a MSI NF980-G65 mobo and AMD Phenom II 965. I am able to use either HP monitors individually or one HP and my Vizio TV together. However when I try to connect the second HP monitor everything goes blank on all active displays, displays flash a no signal message then they all go to sleep. This also occurs when I try to connect both HP monitors at the same time.

Configurations I have tried:
1 HP = works
1 HP + Vizio = works
2 HP = black screens
2 HP + Vizio = black screens

The Vizio is connected via mini-HDMI on card 2. HP monitor 1 is connected to card one using VGA cable to VGA-DVI adapter and plugged into DVI port on card. HP monitor 2 is using a VGA-DVI adapter to a DVI cable then into any available DVI ports on any of my 3 cards. The reason I say "any" port is because I have tried using all available ports (a total of 5 free) with the same result: black screens on all connected monitors. As soon as I disconnect the 2nd HP monitor the others begin working again.

I have tried turning SLI off and just running extended desktop on all three and same results. I have searched for an answer to this on the net and have come up empty. Nvidia website says I should be able to connect 2 displays using any available ports while in SLI mode, this only works with one HP and the Vizio but not the 2 HP's by themselves. All displays are set to 1920x1080 resolution.

Any help is greatly appreciated or links to instructional articles I may not have found. Thank you all.

 

[Mousemonkey]

Why are you using DVI to VGA adapters? That could be the problem right there.

 

[awmcgee]

The HP montiors only have a VGA port and a HDMI port. I was trying to save a little cash and not have to get HDMI cables for all displays. If I used all HDMI cables that would be one display per card which does kind of make sense but my setup has my monitors spread out some so would need a longer HDMI cable = more money. That was going to be a last ditch attempt to solve the problem if I can't find another work around. The thing is both HP montiors work independently. One using a VGA to DVI adapter to connect the cable to the card and the other using a VGA to DVI adapter connecting the display to the cable. It's only when the second HP (either one) is connected that everything goes black.

I'd like to know more about the adapters possibly causing the issue. That interests me cause whats the point of adapters if they screw things up?

 

[awmcgee]

Also none of my cards have VGA ports. All cards are standard 465 config, 2 DVI and 1 Mini HDMI.

 

[Mousemonkey]

I'm pretty sure that all three connections have to be digital at both ends, analogue is no good as it doesn't carry the required info back the the GPU.

 

[awmcgee]

I agree that does make sense, however in that case why am I able to use one of either HP displays (both using adapters though different adapters in different locations) and the Vizio TV at the same time but as soon as the second HP is connected everything goes black? Neither HP is connected through a completely digital connection.

 

[Mousemonkey]

Two might work but three don't and three is the magic number is it not? Just get another DVI or HDMI lead and be done with it.

 

[awmcgee]

True, 3 is the magic number. I'm going to do a bit more searching and see if anyone else posts another suggestion but thank you for your input and if I do find an alternative to more cables I'll post back with the solution. I'm also going to try connecting two displays with HDMI and the third using adapters. Haven't tried that cause it's a pain to get my 360 disconnected