3 monitors not working on ASUS EAH6850, need DisplayPort?

[plzpuddngplz]

I recently purchased a Philips 237E3QPHSU (using HDMI) to act as a third screen in addition to my current Acer X213h (DVI) and Samsung SyncMaster 913V (VGA), which have been working fine for a while. When I try to save settings that would extend the desktop to a third monitor, be it any of the three, I get an "Unable to save display settings" error message.
As stated in the title, my graphics card is an ASUS EAH6850, which I believe should support three monitors, but I can't find any mention of how many monitors the card supports in its documentation.
EDIT: I'm not looking to use Eyefinity, just separate displays.

Googling around seems to suggest that the problem is an active DisplayPort adapter, as I've just plugged the third monitor in through HDMI, but I'd like your advice before I drop the money on an adapter.

Also but probably unrelated, there is a black border around the used part of the screen, almost as if the resolution of the monitor is off. This is a 1920x1080 display, however.
EDIT: This is on the Philips 23", and I can't see the mouse pointer in the black area.
How can I fix this?

TL;DR:
Do I need an active displayport adapter to connect three monitors to a 6850?

Thanks a ton! This is my first time putting together a tri-monitor setup and I'm exited for when everything works!

 

[the great randini]

one does need to be a diplay port.
here are some adapters, i chose the display to vga because my vga monitor was the smallest, but that is just me.

StarTech DisplayPort to DVI http://www.newegg.com/Product/Product.aspx?Item=N82E16882203130

StarTech DisplayPort to VGA Video Adapter http://www.newegg.com/Product/Product.aspx?Item=N82E16815158211

BYTECC Model DPHM-10
http://www.newegg.com/Product/Product.aspx?Item=N82E16812270465

 

[randomkid]

Googling around seems to suggest that the problem is an active DisplayPort adapter, as I've just plugged the third monitor in through HDMI, but I'd like your advice before I drop the money on an adapter.

TL;DR:
Do I need an active displayport adapter to connect three monitors to a 6850?

Yes, an active display port adapter is needed to activate a 3rd monitor. This is because the HDMI & one of the DVI port shares the clock so only one can be active between the two. You can keep the Philips on the HDMI, the Acer on the DVI & get an Active Display port to VGA adaptor for your Samsung.
Getting good active adapters are hit or miss if you are not careful. Here is the AMD certified adapters:
http://support.amd.com/us/eyefinity/Pages/eyefinity-dongles.aspx

 

[randomkid]

Also but probably unrelated, there is a black border around the used part of the screen, almost as if the resolution of the monitor is off. This is a 1920x1080 display, however.
How can I fix this?

To which monitor is this happening?

 

[the great randini]

can you see the pointer in the black bar area, like the desktop background is just not full screen. that can happen if your main monitor is not as high a resolution as you others

 

[a little black duck]

To run eyefinity, the 3rd monitor must be connected via display port. The adapter MUST be active in order to reach the highter resolutions available in eyefinity (5760x1080) A list of approved dongles can be found here http://support.amd.com/us/eyefinity/Pages/eyefinity-dongles.aspx
I would recommend getting an active dp/vga adapter and connecting your phillips monitor via its vga port. Reason behind this is that at this time there are no approved 'active' dp/hdmi adapters. It seems that there are only passive dp/hdmi adapters, there many not even be such a thing as active dp/hdmi.
Good Luck.

 

[AdioKIP]

To fix the issue with the black borders, go into CCC and look for an option called "Overscan", should be a slider of some sorts. You'll need to slide it all the way and that should fix it. When I get home in front of PC I can tell you exactly where it is in CCC.

 

[plzpuddngplz]

Dem responses. Thanks to all of you!

@Randomkid: The black border issue is on the Philips.

@Randini: No, I can't see anything. It's black, as if I had gone into the monitor's OSD and changed the picture size. I can't fix the issue with that, however, as you can only do that if the input is VGA.

@AdioKIP: Thanks for the tip! I found the (well-hidden) overscan bar using the location in this tutorial: http://techhelpbot.com/content/how-change-options-ati-radeons-overscan-or-underscan (Does Tom's support links?).

Black border issue is now fixed thanks to AdioKIP!

As said before, I'm not looking to run Eyefinity, just three separate displays.

So I'll be fine with an active Displayport-to-VGA adapter? I know Randomkid said it was important to get a certified one, but what possible issues could I run into?

Thanks again!

 

[randomkid]

It could flicker ( I had on of this & never get to use the adapter ) or work for a time & die ( I got the same as well which worked only 6 months) or worse, not work at all. I have a limited choice in my country so never have the chance to get the AMD certified. But if you have the choice, better be safe.