Hyper-V, VMware, and VirtualBox Hypervisor Limitations

This is a quick table comparing key features and limitations of some hypervisors available today, such as VMware, Hyper-V, and VirtualBox:

Name	Maximum host cores / CPUs	Maximum host memory	Maximum host disk volume size	Maximum number of guest VM running	Maximum number of logical CPU per VM guest	Maximum amount of memory per VM guest	Maximum number of SCSI + IDE disks per VM guest	Maximum disk size per VM guest
Containers, or Zones	144 cores / 72 CPUs	4 TB	No limit	8191	No limit	No limit	No limit	No limit
VMware Player 4.0	4 cores	No limit	N/A	?	8	8 GB (32-bit); 64 GB (64-bit)	?	2 TB
VMware Server 2.0	16 CPUs	No limit	N/A	64	2	8 GB	4 IDE; 60 SCSI	950 GB
VMware vSphere Hypervisor (ESXi) 4.1	160 logical cores	1 TB	2 TB minus 512 bytes	320	8	255 GB	4 IDE; 60 SCSI	2 TB minus 512 bytes
VMware vSphere ESXi 5.0	160 logical cores	2 TB	64 TB	512	32	1 TB	4 IDE; 60 SCSI	2 TB minus 512 bytes
VMware vSphere Hypervisor (ESXi 5.5) (free)	16 NUMA Nodes / 320 logical CPUs	4 TB	Depending on filesystem	512	8	1 TB	4 IDE; 60 SCSI	62 TB
VMware vSphere Hypervisor (ESXi 5.5)	16 NUMA Nodes / 320 logical CPUs	4 TB	Depending on filesystem	512	64	1 TB	4 IDE; 60 SCSI	62 TB
VirtualBox 4.1.x	256 logical cores (Windows version limited to 64)	No limit	No limit	No limit	32	1 TB	4 IDE; no limit for SATA, SCSI, SAS	2 TB
Hyper-V Server 2008 R2	64 cores / 8 CPUs	1 TB	No limit	384	4	64 GB	4 IDE; 256 SCSI	2 TB
Hyper-V Server 2012	320 cores / 64 CPUs	4 TB	No limit	1024	64	1 TB	4 IDE; 256 SCSI	64 TB

Source: Wikipedia

Backup Software List
BackupChain
Veeam
Unitrends
Symantec Backup Exec
BackupAssist
Acronis
Zetta
Altaro
Windows Server Backup
Microsoft DPM
Ahsay
CommVault
IBM