Central processing unit (CPU) trends
Processors and their relative speed and number of cores have a distinct performance impact on overall system performance. As an example, the latest incarnation of the Intel processors has incremented the number of cores in one of the most popular processors from 20 to 26 per CPU (2 included per motherboard). Through testing it has shown 30% performance improvement at high deduplication rates and a large number of streams. There is also an increase in the speed of the Ethernet NICs from 10 to 25Gb/s, which is the newest "standard" of Enterprise Ethernet. The combination of the two are the only things that have changed from the 5340 system, so the conclusion of additional cores and network bandwidth support the contention of size and speed do matter.
Current processor development is undergoing a significant level of change. AMD has re-emerged and is out pacing Intel with regard to core count and process. At the time of the writing of this document, AMD has a 64 core processor built on 7 nanometer manufacturing process. When compared to Intel at 14 nanometer and maximum core count of 26 it is apparent that Intel is trailing but fighting mightily to maintain their market dominance. There is a significant movement to create processors utilizing the RISK-V architecture. (See https://riscv.org.) This particular architecture, with the combination of a small number of cores and a collection of coprocessor type cores, is an interesting disruptive technology. It is the author's opinion that this space should be monitored as RSIC-V processors have now been designed and implemented on Apple computers as the first step in moving away from Intel processors.
The conclusion drawn from the Cores / PCIe sections above is that significant changes are at our doorstep now and we need to be experimenting with the various platforms to find the best combination. Note the tables above as they detail the evolution of the Xeon processor, especially the number of cores. When NetBackup 7 debuted in 2010, the largest number of cores in a 2U system was 12 using two 6 core processors. 11 years later 52 cores are a popular configuration, an increase of 4 cores per year. This "trend" is not going to change in the near future and as such, when building a system, users must allocate enough cores within the processor(s) to address the number of concurrent operations.