Need Advice: Quadro FX580 or Quadro 1800 ?

Dear friends,
I want to upgrade my videocard. Currently I am using Nvidia 8800 GT.

My choices are below.
One of the card has price almost 3X the other one. (with VAT etc) These are the prices in my country and I can’t afford any higher one.
I wonder does it really make so much difference in persformance and does it worth?
What would you advise me?

Quadro FX 580
512MB GDDR3
$ 248

Quadro FX 1800
768MB GDDR3
$ 625

I also encounter this one Quadro FX 600 which has greater memory but much cheaper than the other ones. What disadvantage does it have?
Quadro FX 600
1GB - GDDR3
$ 233

  [](http://www.hepsiburada.com/Liste/pny-nvidia-quadro-fx580-512mb-gddr3-pci-e-x16-profesyonel-ekran-karti/ProductDetails.aspx?productId=bd53080&categoryId=204)

Thank you everyone.

It depends on what you are going to use it for. For GPU rendering, I would not recommend any of these. For viewport performance, the fx1800 would probably perform better than the other two.

Best regards,
Vladlo

What would you recommend for viewport rendering in this price range?

I would recommend an nVidia GTX 460 2GB version. Should perform very well in your price range.