According to feedback from frontline implementation engineers, the number of CPU cores is related to query concurrency. There are no reports comparing the performance of NebulaGraph Operator and bare metal. The official performance reports are all based on physical machine testing and do not use the Operator, which is just a method of installation. Multiple disks can increase the speed of data import, not all for resisting faults. A customer previously achieved faster import speeds with multiple disks than with a single disk.
The disk size has a related formula, which is multi-linear, so you can proportionally increase or decrease related storage resources linearly.