which processor best for video editing

Neither, I'm afraid. Both of those CPUs are only 4-core/8-thread CPUs to begin with. In addition, the e5-1620 will bottleneck any of the newer GPUs that we normally recommend for a video editing system due to that CPU only supporting PCI-E 2.0 instead of PCI-E 3.0 or 4.0. And while the i7-6700 can run Premiere Pro 14.4, it just does not have the sustainable all-core clock speed to function well for this program. And the E5-1620 will work poorly in Premiere Pro no matter what because its Sandy Bridge architecture just does not have the IPC performance of newer CPUs.

https://community.adobe.com/t5/video-hardware/article-by-dave-helmly-on-hardware-for-running-premiere-pro-aftereffects/td-p/11369321?page=1

The i7 6700, but mind you that it is from 2015 and is considered more or less obselete today when it comes to video editing. The Xeon E5 1620 is from 2012 and is considered as ancient.

Premiere Pro is getting more and more rescource hungry for every version so everything abowe 1080 footage will be frustrating to edit with any of the two processors.