[olug] dual head vid cards

[Kevin D. Snodgrass]

--- On Fri, 1/29/10, Obi-Wan <obiwan at jedi.com> wrote:

> From: Obi-Wan <obiwan at jedi.com>
> Subject: [olug] dual head vid cards
> To: olug at olug.org
> Date: Friday, January 29, 2010, 12:32 PM
> My 64-yr-old dad is about to buy a
> new, low end PC to replace his
> dinosaur.  The dino currently has two vid cards to
> power his two
> 19" CRT's.  Since neither existing vid card will fit
> in any new box,
> he'll need to buy a second vid card if he wants to keep the
> dual
> head setup (and he does).

I assume that is because the old video cards are PCI and/or AGP and any new system will be PCIe, correct?

> Here's my question:  Will most low end PCIe-16 vid
> cards like this one:
>    http://www.newegg.com/Product/Product.aspx?Item=N82E16814127473
> which have one DVI & one VGA port allow you to run both
> ports
> simultaneously as side-by-side monitors, or do you
> typically just
> have to choose one port or the other (or mirror
> them)?  I've seen

If the card is not listed as a dual-head card then it isn't a dual head card.  You need a dual circuitry to drive dual outputs.  The DVI and VGA outputs are included so you can use any monitor from the last 20 years or so. :-)

> If I do only get to run one port on that card, here's
> another question:
> Would I likely be able to run one monitor off the onboard
> video and
> the second one off a PCIe card, or does the PCIe slot
> override the
> onboard slot?

Most mainboards that have built-in video allow you to disable it and run with an add-on card only.  But running with both "should" always work, assuming the video card drivers can handle it.  The mainboard "should" not care what the add-on card is.  Buying standard hardware from a mainline manufacturer almost always gives you standard performance.

> This card is less than half the cost of a dual-DVI card
> (even before
> you buy the DVI-VGA adapters), but I'm wondering if he
> should get a
> $70 dual-DVI card anyway so he's ready when his current
> monitors die.
> This new PC will definitely outlast his monitors.

Is the new PC a "name brand" or are you buying parts?  If buying parts there are mainboards that come with built-in dual head.  I've got one, buy it is an old Athlon board.


Kevin D. Snodgrass