I want to get a windows workstation to run houdini and I'm not sure what are the most important specs to look out for.

More procs with slower clock or less procs with higher clock?

I have a GTX1080TI at home ready to be installed in the machine

For instance I could get one of these 2 machine for similar price:

HP WorkStation Z440
** Intel Xeon Hex Core E5-1650v3 3.5GHz (15M Cache, Turbo to 3.9GHz)
** 32GB 2133MHz DDR4 RDIMM ECC Memory
** 512GB 2.5" SATA SSD (System Drive)
** DVD Super Multi Dual Layer Drive
** NVIDIA GeForce GTX 970 4GB GDDR5 Dedicated Graphics

I would need to add more memory and upgrade power supply on this one to accomodate for the GTX1080TI

or

Dell Precision T7610

Dual Intel Xeon Hex E5-2620v2 2.1GHz (15M Cache, Turbo boost 2.6GHz)
64GB ECC DDR3 1600Mhz Memory
240GB Solid State Drive
1TB 7200rpm SATA HDD
nVidia Quadro K4000 3GB GDDR5 Graphics
Slimline DVD+/-RW Drive
Dual Gigabit Ethernet
1300W Power Supply

The Dell is more expensive but it already has the right amount of RAM and power supply

I'm not particularly attached to these two models, it's just what I have found locally

Thanks
jean-luc