c9429b30_yper_V_VS_Citrix_Xen___My_Blog__Hypervisor_Attributes
[VMware ESXi 5.0] 32-way virtual SMP, 1TB virtual machine RAM, Non hardware accelerated 3D graphics, USB 3.0 device support, Unified Extended Firmware Interface (UEFI). 4-way virtual SMP only, 64 GB RAM per virtual machine [Citrix XenServer 5.6 FP1] 8-way virtual SMP only, 32 GB RAM per virtual machine [Hypervisor Attributes] 
Enhanced Virtual Hardware
Comparison between Vmware VS Hyper-V VS Citrix Xen | My Blog
Hypervisor Attributes