Video Card wont utilize 3rd monitor even though it supports it

[Malcara]

 The card I'm using is the XFX HD-587A-ZNF9 Radeon HD 5870
When I bought this card I got it for both the sheer power, but also because it supports 3 monitors. I've seen pics of people running 2 of these vid. cards in Crossfire mode utilizing 6 monitors. I however am only using 1, because 1 alone nearly over heats my NZXT zero case and its 18 fans. I'm using Windows 7 Ultimate 64 Bit and a Asus Crosshair III motherboard. I've tried using both Windows' default video graphics settings and the vid. cards Catalyst control center to get all 3 monitors to work.
I can only ever get 2 running as 1 must always be disabled, yet both Catalyst and Windows recognizes all 3 monitors it just won't extend the screen between the 3. I have my main monitor the 24" 1080p widescreen (DCLCD DCL24A) attached to the HDMI port and set as main display. My secondary monitor a 1080p 19" square (LG L1933TR) hooked up to one of the 2 DVI ports; Both work fine. Unfortunately when I try and get my (Dell 1503FP) hooked up to the secondary DVI port the computer and video card recognize it, but the screen stays black. When I try to extend video between the 3 It says I have to disable a monitor and when I do the 19" shuts off the 24" switches it resolution to what the 19" had and the 16" dell then turns on.
I can't for the life of me figure out how to get all 3 to work simultaneously.
Any Suggestions.

[Kurtiskain]

The technology for three monitors is "eyefinity" yes?
I havn't had the chance to look at it...I have an HD 4870 so I don't have it but make sure it doesn't need to be enabled first.

[rthompson80819]

I'm sorry, but I got lost at the 18 fans.  The stock NZXT case has eight fans, which is a lot, and you added ten more?

[Kurtiskain]

I'm sorry, but I got lost at the 18 fans.  The stock NZXT case has eight fans, which is a lot, and you added ten more?

I just ignored it as a typo...

Surely 18 fans would be too much throughput? there would be either too much pull or too much intake, possibly just canceling themselves out. I have 8 in my case..
4x 80mm - two on front, one on top, one on side panel with filter.
1x 120mm on back
Stock Core 2 Duo heatsink and fan
Arctic cooling Accellero twin turbo gfx cooler which is 2x 80mm special fans.

And my HD4870 runs idle at 40 decrees Celsius idle without running anything 3D, then full 3d gaming can push it up to 50 Degrees Celsius, but then levels off to about 42 Degrees Celsius afterwards.

The HD 5870 was supposed to have better heat control, but in your case maybe not.

[BC_Programmer]

For eyefinity to work with three monitors, one of the monitors <MUST> be connected via the display port on the card. You can either connect a monitor directly (given it has a display port connection) or by using an active display port adapter. My Google's on the subject seem to indicate that you probably need an Active adapter, although there seem to be a few people who got by with what appears to be passive adapters.

Anyway, the root of the problem is essentially hardware-based; when anything is connected to the HDMI port, the card disables one of the DVI ports, which is why three monitors won't work without using the display port.