Quadro cards have enabled some special features (electrical and software) which are useful for CAD or other special software applications,
they have special drivers which provide presets for these apps. "Consumer" are more tuned to games.
In the early days you could tune Geforce cards to Quadros via soldering or software hacks. Because they were the same design.
Since Terragen does not use any of the features (atm) any GPU can provide there is not much to say against a Quadro.
But remember that the architecture of the card is already 7 years old!
In computer terms that is about as old as some of the times you depict in your work
I would not shelf out the extra money for that K6000 anymore, but go for a modern card.
Since you said in another thread that they are hard to find and buy just wait for them.
Any other application you seem to be using (Speedtree, ZBrush, Marvelous Designer or
Substance Painter (in the future perhaps)) will have features sometime that are not supported
fully on those cards. If that is not already the case.
For Terragen, Daz and Lightwave the Kepler Quadro is still good enough, of course.
I would be interested to know where Matt is going with GPU development.
He surely could advise you/us better regarding which card would be useful.
As I said in September in your thread about buying a new machine: more VRAM is better. So the 12gb are a good thing.
But not necessarily on this Quadro K6000 anymore. They are slow compared to more modern architecture.
If it is worth the money for you it sure is a useful upgrade. In two or three years time you will have to change the GPU, I think.
Regarding the computer specs itself, it will be a step forward to your present setup for sure.
If you look at the benchmark again you`ll see that the XEONs do quite well. But be sure to go for a dual XEON setup.
One cpu is quite slow compared to the AMD you were thinking about. Remember that the XEONs render with a slower core speed,
not with the max speed given. This only is used for 1 one core use. So do not think your image will be rendered with 3.5ghz....
A lot of the i-7 cpus (from generation 7 onwards I`d say) are better for day to day work because of the higher clock speed
and the possibility of overclocking better (the K models at least) than the XEONs. But less cores might take more time to render.
Even with higher clocked speed. Again, look at the benchmark results.
I`d still go with AMD now if I were you, since you do not seem to upgrade very often.
"He who buys cheap buys twice" as they say...
CHeers, Klaus - (Sorry for this lenghty post)