EquineHero :
I have two Quadro 4000s in my animation workstation right now and for my current animation, it takes about 4 hours to render 10 minutes of actual content ready for post-processing. Using my 1070 for the same animation takes about 5 and a half hours despite being Pascal and much, much faster. The 5000 is not twice as fast as the 4000s together but each 4000 was around $80.
I won't have any additional money until after I finish with this animation so the faster it gets done, the better Quadro I can get. If you need more details I can provide them.
So you are actually planning on using the card for rendering in Cycles? In that case I must warn you that Fermi has some weird issues with Cycles. Several of the problems that I read about being fixed are all issues that I have faced when using a Tesla C2075 and C2050. The most notable one being some arbitrary limits on textures and geometry compounded by their relation to each other in VRAM (no matter how much is actually being used) but if you are not getting any CUDA errors then I guess your scenes are not intense enough to trip these anomalies.
The real thing though is those numbers for your rendering times make no sense. The BMW GPU Benchmark takes 2:50-3 minutes to render on one of my two GTX 1070s in my dual Xeon 2680v2 64GB DDR3 1866MHZ HP z620, scaling almost one-to-one with both cards together averaging a minute-thirty. My k4000, which is 10-15% slower than my Teslas, takes over 14 minutes!
What are your render settings because the 1070 should be so much faster.
Also, without touching any settings run the Blender BMW GPU Benchmark and tell me what times you get: https://www.blender.org/download/demo-files/
I am really curious as to what is going on here.