GTX 660 sufficient as GPU?

[Hallihallo]

Hello!
I'm trying to put together a hardware configuation, which I'll mainly use for things like GIS, image-processing, layouting-work, office work, and hopefully Photoscan as well (in the future; would be nice if the computer was powerfull enough to create modells with up to e.g. 200 pictures at least).

I've more or less decided about most parts of the configuration, which looks as follows:
CPU Core i7-4930 K 6*3,40 GHz TM bis 3,9 GHz
GPU NVIDIA GeForce GTX 660 3GB GDDR5 HDMI, DVI, VGA, DP, DX 11.1
Memory 64GB 1600Mz DDR3 PC3-12800 (8*8GB)
System HDD   240 GB SSD 2,5“ SATA 6GB/s bis zu 550MB/s Datentransfer
Daten HDD   3TB SATAIII 6GB/s 64MB Cache 7200rpm RAID m?glich
Mainboard   AsRock X79 Extreme9 USB3, GBLAN, 6GB/s SATA3, UEFI
....

The only thing I'm really uncertain about is the GPU. As I don't play games etc. I don't think I need an especially powerfull GPU and at the moment I'm thinking about choosing the NVIDIA GeForce GTX 660 3GB GDDR5 HDMI, DVI, VGA, DP, DX 11.1 . Is this sufficient? or would this be the one week point of the current computer configuration - which will annoy me for years to come ... Is it indispensable, that I should upgrade and spend the additional money e. g. for the AMD Radeon HD 7970 3GB GDDR5??
Thank you very much for information!

[meshmixup]

Hi there, To this level of CPU performance to handle 200+ photos, you need higher grade GPU(S) to boost the depth reconstruction process. Many users here are equipped with 2 or more GPU cards

[Oli63]

As far as I know the AMD 7970 (and most probably its successor R9 280X) doubles the performance of the NVidias for a significantly lower price. Wishgranter knows more about this issue.

[Hallihallo]

Thanks a lot! Will take one AMD 7970 in that case!