Quadro K4200 4GB or GTX 980 4GB ?

RIGHT !

GTX 900 series graphic cards are not supported for now from ADOBE Developers to get nvidia drivers and to certify them as ADOBE SIGNED GTX 900 DRIVERS as Nvidia do with Microsoft for Windows (WHQL-Windows Hardware Quality Labs)...for now GTX 900 GPUs work practicully Based on CUDA API and the GPU GM204 isnide of GTX 980 works without Maxwell Improvements but it reacts as a old Fermi or Kepler one.

Now for the moment all beasts as HP Z840 , Precision T7810 , Celsius R940 , Thinkstation P900 are based on Quadro Cards because the drivers signed for this GPUs has ISV Certifications for all media , including here and Decoders and Encoders on VIDEO for AE and PR.

Its not important to select a GPU that has a lot of Gpixel/s or Gtexel/s or a lot of memory bandwidth (ok they are importat  buuut..)...Select a certified GPU as the first Like Quadro 2000/4000/5000/6000 Low Budget now and Quadro K 2000/2200/4000/4200/5000/5200 or Special Game GPUs that are Certified for AE and PR  ,GTX 780 ,GTX Titan and GTX 780 Ti and than see the specs.

My preferred GPU is ASUS STRIX GTX 780 6GB with real time 4K 60fps footage playback.

Santhi,

I agree with Eric. Go for the GTX 980. Here's why:

1) The GTX 980 is based on the newer second-generation Maxwell architecture, which means that it will more likely support newer technologies than the Quadro K4200 (which is still based on the first-generation Kepler architecture despite being part of the newest Quadro lineup).

2) The K4200 is, if anything, slightly slower in performance than even a $200 GeForce GTX 760, let alone a GTX 980. That's because despite the 1,344 CUDA cores in the K4200 (versus 1,152 CUDA cores in the GTX 760), the K4200's GPU core clock speed is 25 percent slower than that of the boosted reference-clocked GTX 760 - 780 MHz versus 1,033 MHz. This significantly lower clock speed is too great for the extra CUDA cores to compensate for. In addition, the K4200's memory throughput is significantly lower than that of even the GTX 760, let alone the GTX 980: 173 GB/second for the K4200 versus 192 GB/second for the GTX 760 and 224 GB/sec for the GTX 980.