Q. Will this new video card work in my machine?

The questions you always have to ask when installing a new video card in a desktop or tower machine are:

• Is there an available PCI-e x16 slot with space beside it for the video card’s fans?
• Is there physical room in the chassis for a larger video card (many small form factor or minitower machines can’t take a full height-full length card)?
• Does the power supply have enough Watts to support the card?  Check the video card manufacturer’s website for minimum system requirements.  This website has a calculator that can help estimate power supply requirements
• Does the power supply have the correct PCI-e power connection cable for the video card if the card requires it?
• For Dual-Video-Card setups (SLI or CrossFire) does the motherboard have the slots and does it support the technology?

Keep in mind most inexpensive Dell, HP and Compaq machines have 300W (or lower) power supplies.  Mid-performance and above Radeon and GeForce cards require at least 400W – 500W.

So to consider a card, you may have to replace the power supply of the computer as well.
You would need to check whether the machine has the space and the mounting screw holes correct for a standard ATX power supply.  (Some HP, Compaq, Dell and many slim line machines use smaller non-standard power supplies which are difficult to find replacements for).

For notebook computers, almost all notebooks have non-upgradeable video.

Comparisons of graphic cards
http://www.gpureview.com/
http://www.tomshardware.com/charts/graphics-cards,1.html
http://www.videocardbenchmark.net/
Benchmarks for specific games: http://www.guru3d.com/article/vga-charts-spring-2011/
Notebook graphic chip performance chart: http://www.notebookcheck.net/Comparison-of-Laptop-Graphics-Cards.130.0.html