Below are a comprehensive collection of configuration maximums from VMware products

Virtual Machine MaximumsHost MaximumsvCenter Server MaximumsCluster and Resource Pool MaximumsNetwork MaximumsStorage Maximums

Virtual Machine Maximums

ESX 5.5
ESX 5.1
ESX 5
ESX 4.1
ESX 4.0
ESX 3.5
ESX 3
ESX 2
ESX 1
Virtual CPUs per virtual machine 64 64 32 8 8 4 4 2 1
RAM per virtual machine 1TB 1TB 1TB 255GB 255GB 65GB 16GB 3,6GB 2GB
Virtual SCSI adapters per virtual machine 4 4 4 4 4 4 4 4 4
Virtual disk size 62TB 2TB 2TB 2TB 2TB 2TB 2TB
IDE controllers per virtual machine 1 1 1 1 1 1
IDE devices per virtual machine 4 4 4 4 4 4
Floppy controllers per virtual machine 1 1 1 1 1 1 1 1
Floppy devices per virtual machine 2 2 2 2 2 2 2 2
Virtual NICs per virtual machine 10 10 10 10 10 4 4 4 4
USB controllers per virtual machine 1 1 1 1
USB devices connected to a virtual machine 20 20 20 20
Parallel ports per virtual machine 3 3 3 3 3 3 3 1
USB 3.0 devices per virtual machine 1 1
Concurrent remote console connections 40 40 40 40 40 10 10

Host Maximums

ESX 5.5
ESX 5.1
ESX 5
ESX 4.1
ESX 4.0
ESX 3.5
ESX 3
ESX 2
ESX 1
Logical CPUs per host 320 160 160 160 64 32 32 16 8
Virtual machines per host 512 512 512 320 320 128 128 80 64
Virtual CPUs per host 4096 2048 2048 512 512 128 128 80 64
Virtual CPUs per core 32 25 25 25 20 8 8 8 8
RAM per host 4TB 2TB 2TB 1TB 1TB 256GB 256GB 64GB 64GB
LUNs per server 256 256 256 256 256

vCenter Server Maximums

vCenter Server Maximums
ESX 5.5
ESX 5.1
ESX 5
ESX 4.1
ESX 4.0
ESX 3.5
ESX 3
Hosts per vCenter Server 1000 1000 1000 1000 300 200 200
Powered on virtual machines 10000 10000 10000 10000 3000 2000
Registered virtual machines 15000 15000 15000 15000 4500 2000
Linked vCenter Servers 10 10 10 10 10
Hosts in linked vCenter Servers 3000 3000 3000 3000 1000
Powered on virtual machines in linked vCenter 30000 30000 30000 30000 10000
Registered virtual machines in linked vCenter 50000 50000 50000 50000 15000
Concurrent vSphere Clients 100 100 100 100 30
Number of host per datacenter 500 500 500 400 100
MAC addresses per vCenter Server 65536 65536 65536
USB devices connected at vSphere Client 20 20 20

Cluster and Resource Pool Maximums

ESX 5.5
ESX 5.1
ESX 5
ESX 4.1
ESX 4.0
ESX 3.5
Hosts per cluster 32 32 32 32 32 32
Virtual machines per cluster 4000 4000 3000 3000 1280
Virtual machines per host 512 512 512 320 100
Maximum concurrent host HA failover 32 32 4 4
Failover as percentage of cluster 100% 100% 50% 50%
Resource pools per cluster 1600 1600 1600 512 512 128
Resource pools per host 1600 1600 1600 4096
Children per resource pool 1024 1024 1024 1024
Resource pool tree depth 8 8 8 8 12 12

Network Maximums

ESX 5.5
ESX 5.1
ESX 5
ESX 4.1
ESX 4.0
ESX 3.5
ESX 3
Total virtual network switch ports per host 4096 4096 4096 4096 4096 127
Maximum active ports per host 1016 1050 1016 1016 1016 1016
Virtual network switch creation ports 4088 4088 4088 4088 4088
Port groups 512 256 256 512 512 512
Distributed virtual network switch ports per vCenter 60000 60000 30000 20000 6000
Static port groups per vCenter 10000 10000 5000 5000 512
Ephemeral port groups per vCenter 1016 256 256 1016
Hosts per VDS 500 500 350 350 64
Distributed switches per vCenter 128 128 32 32 16
e1000 1Gb Ethernet ports (Intel PCI?x) 32 32 32 32 32 32
e1000e 1Gb Ethernet ports (Intel PCI?e) 24 24 24 24 32 32 32
igb 1Gb Ethernet ports (Intel) 16 16 16 16 16
tg3 1Gb Ethernet ports (Broadcom) 32 32 32 32 32
bnx2 1Gb Ethernet ports (Broadcom) 16 16 16 16 16
forcedeth 1Gb Ethernet ports (NVIDIA) 2 2 2 2
nx_nic 10Gb Ethernet ports (NetXen) 8 8 8 4 4
ixgbe 10Gb Ethernet ports (Intel) 8 8 8 4 4
bnx2x 10Gb Ethernet ports (Broadcom) 8 8 8 4 4
be2net 10Gb Ethernet ports (Emulex) 8 8 8 4 4
VMDirectPath PCI/PCIe devices per host 8 8 8 8 8
VMDirectPath PCI/PCIe devices per virtual machine 4 4 4 4
Concurrent vMotion operations per host (1Gb/s network) 4 4 4 2 2
Concurrent vMotion operations per host (10Gb/s network) 8 8 8

Storage Maximums

ESX 5.5
ESX 5.1
ESX 5
ESX 4.1
ESX 4.0
ESX 3.5
ESX 3
Qlogic 1Gb iSCSI HBA initiator ports per server 4 4 4 4
Broadcom 1Gb iSCSI HBA initiator ports per server 4 4 4 4
Broadcom 10Gb iSCSI HBA initiator ports per server 4 4 4 4
Software iSCSI NICs per server 8 8 8 8
Number of total paths on a server 1024 1024 1024 1024
Number of paths to a iSCSI LUN 8 8 8 8
Qlogic iSCSI: dynamic targets per adapter port 64 64 64 64
Qlogic iSCSI: static targets per adapter port 62 62 62 62
Broadcom 1Gb iSCSI HBA targets per adapter port 64 64 64 64
Broadcom 10Gb iSCSI HBA targets per adapter port 128 128 128 64
Software iSCSI targets 256 256 256 256 256
NFS mounts per host 256 256 256 64 64
FC LUNs per host 256 256 256 256 256 256 256
FC LUN ID 255 255 255 255 255 255 255
FC Number of paths to a LUN 32 32 32 32 32 32 32
Number of total paths on a server 1024 1024 1024 1024 1024 1024 1024
Number of HBAs of any type 8 8 8 8 8
HBA ports 16 16 16 16 16 16
Targets per HBA 256 256 256 256 256 15
Software FCoE adapters 4 4 4
Volumes per host 256 256 256 256 256 256
Hosts per volume 64 64 64 64 64 32
Powered on virtual machines per VMFS volume 2048 2048 2048 256
Concurrent vMotion operations per datastore 128 128 128
Concurrent Storage vMotion operations per datastore 8 8 8
Concurrent Storage vMotion operations per host 2 2 2
Concurrent non vMotion provisioning operations per host 8 8 8
VMFS Volume size 64TB 64TB 64TB 64TB 64TB 64TB