Do I really need NVIDIA SLI?

My custom-build is for the following uses:
Teach myself various operating systems~ It will have three dedicated hard disc drives (mobile-rack type). One for XP Pro. One for Linux Mint. One for trial of various Linux and BSD distros.

Photoshop & GIMP~ Saw guy on tv who edits out faces in famous paintings, and replaces with his cats face. Sounds like my new hobby.

Video work~ Need to convert my PAL/Secam foreign movies to NTSC DVDs; convert videos to DVDs; watch free 'Internet TV' and record TV shows to DVD.

Miscellany~ Explore internet, shop, print out Google Photos via B&W laser and color inkjet, etc.

Do I need two graphic cards for this or not?

 

Nope , not necessary unless you game heavily.

 

Buy a board that is SLI compatible (2 video card slots) and a decent video card that supports SLI. Also, use a decent power supply (such as Corsair's high-end series) of at least 600 watts.

You may never decide to add a second video card for SLI; however a build like this gives you an option to do so later if needed.

 

Spend some decent money on a high memory well specified video card at the outset and you shouldn't need a second card - as augiedoggie suggested you don't really need to SLI two cards unless you're spending all your time gaming!!

You potentially only benefit when using the Windows OS anyway.

Be aware too, that the higher-end graphics cards require additional power so make sure the PSU has plenty of watts and has the necessary power plugs to fit your card; without the additional power the card won't run to its full potential.

Sounds like an exciting project - good luck with it.

 

@ Senex The best bang for the buck is the GTX560Ti if you can afford it. As to converting video formats, that's done by the CPU.