I currently have two monitors running on an add-on ATI video card that came with my 3 year old Dell E510. I have a third monitor coming soon (man, 24 inchers are cheap now) but I just found out that I cannot use the on-board graphics to drive it. Apparently Dell BIOS disables it when an add-on card is detected. So I am looking for a second card. I have one PCI and one PCIE-1x slots open. Am I OK with a 305W power supply? I don't need a fancy gaming card -- I just want a cheap upgrade to display more charts (without slowing down CPU much). Any recommendations? Thanks.
running a third monitor will require you install another video card. You might as well get another dual output video card in case you decide to get another monitor in the future......you can find a good one for about $70-$80 thru newegg.com tigerdirect.com, etc. if I were you i would get a PCI card and save the PCIE slot for something else. In terms of your powersupply: you need to upgrade to at least a 500 watt unit or you risk overloading the one you have now. 305W just isnt enough..
305W PSU is probably OK unless you run high wattage gaming video card. At a minimum, you should try it with your video cards before replacing for bigger.
Is there any way to tell if I am doing okay with PSU besides seeing system unstability? I am fairly computer literate but I am kind of green on graphics cards and PSU.
The average modern computer draws about 150-180W at idle... Many, only about 120-130W. A video card for trading and without a fan will add only about 15-30W to the total load. The monitors aren't an issue for the PSU.. only the video cards. There are meters which will measure the total load... link is an example. http://www.earthtechproducts.com/p236.html
You are better off with two of the same video cards because dissimilar cards often result in driver conflict - even when both are made by the same manufacturer. Try to find one of the same card you presently have even if its used. For PSU demand, there are many online calculators which you can use to determine if you need a larger psu. Try newegg and ocz - both have decent calculators.
actually the easiest solution is to get a usb2 - dvi adapter. Most cards will give you the dual dvi then the usb will be for your 3rd monitor. Example: http://www.iogear.com/product/GUC2020DW6/
These things must be quite slow compared to a proper card. USB is very slow compared to PCI-E. You can get a proper card for less money.