vps_dxb,
Last evening, a search to find differences / comparisons in architecture between Xeon E5 v2, v3, and v4 did bring up an interesting aspect.
What may be worth looking into further is the Pix4D recommendation to disable hyperthreading. Using previous series CPU's many video games, a non-hyperthreading core i5 produced better results than a 6-core hyperthreading i7. Disbaling hyperthreading lowers latency on polygon posititional calculations and the faster GPU VRAM takes over more the 3D visualization processing. As the Xeon E5's have progressed, the CAS rating of the RAM continues to increase, but the actual latency due to the higher memory clock speed is lower. The memory bandwidth of LGA2011-3 E5's are greater than v2's as well. If Pix4D suggests disabling hyperthreading, the fault is possibly somewhere in the paraellization /memory utilization. With a large dataset, is the lower actual RAM latency of E5 v3's DDR4-2133 overwhelming the CPU clock speed when hyperthreading- a CPU bottleneck? This situation with a dual CPU system using ECC registered as the one cycle delay that in a sense guarantees the thread synchronization between two CPU's could exacerbate the problem. This could be a naive assessment however.
What is the processor in the Mac?
It occurred to me that servers deal with large throughput at high rates and servers often use somewhat lower clock speed CPU's. A interesting article on optimizing BIOS settings:
BIOS optimizations for Xeon E5-2600 v3 based systems
In the absract of the paper:
"Its purpose is to optimize BIOS settings according to requirements. The objectives here are to optimize PRIMERGY servers for best performance and maximum energy efficiency. In addition to optimization for maximum throughput, application scenarios are also taken into account, in which the shortest possible response time matters.
Of course, the settings of the systems aren't the same as for a z840, but the nature of the recommendatiosn may apply.
Just to eliminate it as possibilities: have you checke that hibernation is disabled and the power scheme is set to "high performance" on your system? It's been some time, but twice, I've have had those reset by Windows updates.
Does Pix4D offer a trial of their software and sample problems?
Cheers,
BambiBoom