three DVI monitors, low power?

They make noise, too.

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colin2
Posts: 145
Joined: Wed Jul 11, 2007 2:40 pm
Location: Seattle

three DVI monitors, low power?

Post by colin2 » Sat Jan 17, 2015 1:42 pm

I have this thing: SPARKLE 700003 GeForce GT 640 2GB 128-Bit DDR3 PCI Express 3.0 x16 HDCP Ready Video Card

After two years one channel has crapped out.

My usage is office-type stuff - hardly any video or gaming. The PC has a 380W Antec PSU

What I'm seeing is that currently-available graphics cards with three physical DVI connectors are power-hungry beasts made for gaming.

Lower-power multi-monitor cards now seem to use Displayport connectors. Should I go with those, and hope that they really can output a DVI signal through the Displayport connectors? The physical connection seems easy enough, but I'm seeing a certain hesitancy about how well Displayport cards can talk to DVI monitors. Or would a card with multiple HDMI outputs be able to service DVI monitors?

My current monitors are two HP LP2065 (1600x1200) plus one HP L2445w (1920 x 1200).

washu
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Joined: Thu Nov 19, 2009 10:20 am
Location: Ottawa

Re: three DVI monitors, low power?

Post by washu » Sat Jan 17, 2015 2:17 pm

The simplest solution is to make sure you get Active displayport to DVI converters, not passive ones. Most current video cards only have two TDMS channels so they can only output any two DVI/HDMI signals. A passive converter takes one of those channels, an active one does not.

HDMI and DVI are electrically the same so a passive converter will work fine. However, the above about two TDMS channels still applies. The common configuration of 2 DVI + 1 HDMI can only use 2 of them total at once, not three. Make sure to check the specs of your video card careful.

I had a setup of DVI, HDMI -> DVI (passive adatper), Displayport -> DVI (active converter) & Displayport for 4 monitors total on one card which worked fine.

Another option if your system supports it is two even lower power cards. I ran 2 X AMD 4350 on a different system with 4 monitors and it worked fine. For office work even if the second card is on an PCIe 2.0 x4 slot it's still more than fast enough. Or just use your onboard video for one monitor if that is an option.

CA_Steve
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Re: three DVI monitors, low power?

Post by CA_Steve » Sat Jan 17, 2015 5:08 pm

Doesn't the motherboard have a graphics port? Use that.

colin2
Posts: 145
Joined: Wed Jul 11, 2007 2:40 pm
Location: Seattle

Re: three DVI monitors, low power?

Post by colin2 » Mon Jan 19, 2015 6:15 pm

Thanks! This is very helpful. Mobo is a GIGABYTE GA-MA78GPM-UD2H. I'm not aware of a "graphics port" and last I checked, you could not simultaneously use the mobo's own video output and a video card.

Perhaps the time has come to buy one of these:

http://www.matrox.com/graphics/en/produ ... lppciex16/

plus active adapters. Not cheap, but fanless, and Matrox is aiming directly at my kind of usage.

washu
Posts: 571
Joined: Thu Nov 19, 2009 10:20 am
Location: Ottawa

Re: three DVI monitors, low power?

Post by washu » Mon Jan 19, 2015 7:12 pm

Your motherboard has both a DVI (which solves you problem) and and HDMI port which could easily be converted to DVI. Try enabling it in your BIOS, it will probably work and solve your problem for free. Unless you are running Vista your onboard and GT640 should run fine together

That matrox is an incredibly poor value. Even of you want to get a new card there are much better options. You can get a fanless R250 for less than 1/3 the price.

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