Resource Intensive Calculation - help select CPU

Hi,
I am selectign a cpu for rather hard - 24-hour calcuations. I am selelectign between these cpus:

Xeon-E5-2680 (16 cores, lower core speed) and Xeon-E5-1650 (12 cores, much higher lower core speed).

I wonder which is best for excel??

http://cpuboss.com/cpus/Intel-…680-vs-Intel-Xeon-E5-1650

Please let me know

Dorian