I recently purchased a Dell XPS-8300 (i7-2600|16 GB DDR3 RAM|64-bit Windows7) which I intend to use primarily for GIS programs. I bought a refurbished model because it was much cheaper and because I am able to choose a graphics card of my own.
I am currently in the process of purchasing said card, but I haven't really seen much information about what kinds of cards are optimal for ArcMap or QGIS rendering as opposed to Battlefield 3 or Skyrim.
I am currently looking at an XFX AMD Radeon HD6870 PCIE 2GB Dual Mini or an XFX AMD Radeon HD 6870 900M 1 GB DDR5 DUAL MINIDP HDMI DUAL DVI PCI-E Video Card
The 2 GB model is about $40 more than the 1 GB.
I have a 460 watt power supply and do not know if the extra ram affects power consumption. The 1 GB model, from all reviews, should work fine with my system, so I am hoping the 2 GB would work fine as well.
However, since I already have 16 GB of onboard ram and have read that GPU RAM isn't really important unless you go under the amount needed for a given program and settings, I am wondering if this extra GB would be worth it for my purposes:
For example if I have a parcel dataset with hundreds of thousands of polygons, would that extra GB of GDDR5 RAM significantly improve the time it takes to render the polygons when I scroll/zoom in on ARCmap/QGIS; or does it mostly worthless due to the fact that I already have 16 GB that can be used?
Also are there any specific advantages/disadvantages to using a ATI vs NVIDIA card for GIS display programs in general?