If you're using XP(32 bit, I think), the system (mine, anyway) will only show about 3.25GB of RAM. I have physically 4GB, system info "reports/shows" 3.25GB. In XP Pro at least, the boot.ini will need to contain the /3gb in the line. Search the "computer hardware" forum for details. You'll need/want an external HDD also. (update for spelling)
I just upgraded from a 4mp sensor to a 12mp sensor, and my 2004-vintage computer is holding up just fine. Obviously things aren't as quick as they were before, but they're not agonizingly slow either. I have a 1.8 GHz AMD with single core and 2 GB memory. On the other hand, I don't use NX either - I use Photoshop.
Actually, the thing that's the biggest difference is simply how long it takes to download images into the computer, and that's really a function of the reader and card speed rather than anything in memory or CPU. And it's easy to just walk away while that's happening, too.
_____ Brian... a bicoastal Nikonian and Team Member
My gallery is online. Comments and critique welcomed any time!
Brian, I was using an 1.8 AMD with 1 GB Sdram memory until a few weeks ago when I went to a 2.6 Quad with 4 GB DDR2. Photoshop never noticed the difference. However, Norton can now do a full scan in the background in less the 1/4 the time without slowing me down.
I had a D300 so the file size is the same as the D700/D3. My computer is over two years old with a Pentium 4 3.2 processor (non of that dual and quad stuff). I have upgraded my RAM form 1 to 2 and recently 3GB. I use NX and Photoshop and no problems at all. At 2GB RAM it strained once in a while, with only 1 it choked and died often
Albert J Valentino Nikonian Moderator Emeritus Vantage Point Images Mastery of Composition is the Key to Great Photography