Please add some more details about what the problems are, "performance issues" does not say much...
Is it disk, cpu, memory, graphics, pcoip-traffic, mouse-lag or something else?
How are the virtual machines configured? vCPU:s, memory, disk
Are 3D rendering configured? If so are you using software or hardware? If hardware are you using vSGA or vDGA?
Are you using PCoIP or RDP? Any optimizing done on that?
// Linjo