c9429b30_yper_V_VS_Citrix_Xen___My_Blog__Hypervisor_Attributes
[VMware ESXi 5.0] AMD RVI, Intel EPT large memory pages, universal 32-way vSMP, VMI paravirtualization, VMDirectPath I/O, PV guest SCSI driver Large memory pages, 4-way vSMP on Windows 2008 and Windows 7 VMs only [Citrix XenServer 5.6 FP1] No large memory pages, no paravirt guest SCSI device, Requires inflexible SR-IOV [Hypervisor Attributes] 
Performance Enhancements
Comparison between Vmware VS Hyper-V VS Citrix Xen | My Blog
Hypervisor Attributes