Hi,

I recommend you to  use PCI NVME for cache and normal SSD for capacity drives. In real world Full ssd vsan configs beats the full NVME optane configs. Using all Optane NVME drives does not come with the big performance difference . One of my customer have all Optane NVME 6 node they can only get 150K IOPS in 1ms aggregated latency with 16k block size. The other customer have 6 all flash ssd nodes and they get the 200k with the same tests in 1ms. The tests were done by DellEMC team .