Most system (hardware) requirements on a single page. I hope it will be useful to you. I also have added the links to the source.
vSphere vCenter Server Appliances 7.0 (VCSA)
| Product | Size | vCPU | vRAM | Storage | Comment |
| vCenter VCSA | tiny | 2 | 12 GB | 315 GB | 10 hosts and 100 VMs default storage |
| vCenter VCSA | tiny-lstorage | 2 | 12 GB | 1390 GB | 10 hosts and 100 VMs large storage |
| vCenter VCSA | tiny-xlstorage | 2 | 12 GB | 3145 GB | 10 hosts and 100 VMs x-large storage |
| vCenter VCSA | small | 4 | 19 GB | 380 GB | 100 hosts and 1,000 VMs default storage |
| vCenter VCSA | small-lstorage | 4 | 19 GB | 1435 GB | 100 hosts and 1,000 VMs large storage |
| vCenter VCSA | small-xlstrorage | 4 | 19 GB | 3195 GB | 100 hosts and 1,000 VMs x-large storage |
| vCenter VCSA | medium | 8 | 28 GB | 600 GB | 400 hosts and 4,000 VMs default storage |
| vCenter VCSA | medium-storage | 8 | 28 GB | 1600 GB | 400 hosts and 4,000 VMs large storage |
| vCenter VCSA | medium-xlstorage | 8 | 28 GB | 3360 GB | 400 hosts and 4,000 VMs large storage |
| vCenter VCSA | large | 16 | 37 GB | 965 GB | 1,000 hosts and 10,000 VMs default storage |
| vCenter VCSA | large-lstorage | 16 | 37 GB | 1665 GB | 1,000 hosts and 10,000 VMs large storage |
| vCenter VCSA | large-xlstorage | 16 | 37 GB | 3425 GB | 1,000 hosts and 10,000 VMs x-large storage |
| vCenter VCSA | xlarge | 24 | 56 GB | 1705 GB | 2,000 hosts and 35,000 VMs default storage |
| vCenter VCSA | xlarge-lstorage | 24 | 56 GB | 1805 GB | 2,000 hosts and 35,000 VMs large storage |
| vCenter VCSA | large-xlstorage | 24 | 56 GB | 3565 GB | 2,000 hosts and 35,000 VMs x-large storage |
NSX Data Center for vSphere, 6.4
| Product | Size | vCPU | vRAM | Storage |
| NSX Manager | regular | 4 | 16 GB | 60 GB |
| NSX Manager | large | 8 | 24 GB | 60 GB |
| NSX Controller | Compact | 1 | 512 MB | 1 x 584 MB 1 x 512 MB |
| NSX Controller | Large | 2 | 1GB | 1 x 584 MB 1 x 512 MB |
| NSX Controller | Quad-Large | 4 | 2 GB | 1 x 584 MB 1 x 512 MB |
| NSX Controller | X-Large | 6 | 8 GB | 1 x 584 MB 1 x 2 GB 1 x 256 MB |
| Guest Introspection | N/A | 2 | 2 GB | 5 GB (Provisioned space is 6.26 GB) |
NSX-T Data Center, 3.0
| Product | Size | vCPU | vRAM | Storage | Comment |
| NSX Manager | Extra Small | 2 | 8 GB | 200 GB | Cloud Service Manager Only |
| NSX Manager | Small | 4 | 16 GB | 200 GB | For Lab or PoC |
| NSX Manager | Medium | 6 | 24 GB | 200 GB | |
| NSX Manager | Large | 12 | 48 GB | 300 GB | |
| NSX Edge VM | Small | 2 | 4 GB | 300 GB | For Lab or PoC |
| NSX Edge VM | Medium | 4 | 8 GB | 300 GB | Typical Production Environment |
| NSX Edge VM | Large | 8 | 32 GB | 200 GB | Typical Production Env w/ Load Balancing |
| NSX Edge VM | Extra Large | 8 | 64 GB | 200 GB | Typical Production Env w/ Load Balancing |
vRealize Operations Manager 8.1
https://kb.vmware.com/s/article/78495
For storage requirements please see Sizing Guideline Spreadsheet attached to above link.
| Product | Size | vCPU | vRAM |
| vRealize Operations Node | Extra Small | 2 | 8 GB |
| vRealize Operations Node | Small | 4 | 16 GB |
| vRealize Operations Node | Medium | 8 | 32 GB |
| vRealize Operations Node | Large | 16 | 48 GB |
| vRealize Operations Node | Extra Large | 24 | 128 GB |
| Remote Collector (RC) | Standard | 2 | 4 GB |
| Remote Collector (RC) | Large | 4 | 16 GB |
vRealize Log Insight 8.1
https://kb.vmware.com/s/article/60355
For storage requirements please see Sizing Calculate attached to above link.
| Product | Size | vCPU | vRAM | Comment |
| vRealize Log Insight | Extra Small | 2 | 4 | Log ingest Rate: 6 GB/day Events per Second: 400 |
| vRealize Log Insight | Small | 4 | 8 | Log ingest Rate: 30 GB/day Events per Second: 2000 |
| vRealize Log Insight | Medium | 8 | 16 | Log ingest Rate: 75 GB/day Events per Second: 5000 |
| vRealize Log Insight | Large | 16 | 32 | Log ingest Rate: 225 GB/day Events per Second: 15000 |
vRealize Orchestrator 8.1
| Product | vCPU | vRAM | Storage |
| vRealize Orchestrator | 4 | 12 GB | 200 GB |
vRealize Suite Lifecycle Manager 8.1
| Product | vCPU | vRAM | Storage | Comment |
| Lifecycle Manager | 2 | 6 GB | 48 GB | Thick Provisioned |
vRealize Automation 8.1
| Product | vCPU | vRAM | Storage | Comment |
| vRealize Automation Appliance | 12 | 40 GB | 222 GB | |
| Identity Manager | 2 | 6 GB | 60 GB |
TXUSA 