The answer is 0, if you want a supported configuration. The HCL lists the DL360 G5 as supported with 5.1 U2, 5.1 U1, 5.0 U3, and 5.0 U2 only.
Assuming you went with a supported config or could get ESXi 5.5 to install - what types of workloads are you planning to run. The question is a tough one to answer without more detail about the VMs themselves.
Thanks for the information. Yes, looking at it the supported config is only ESXi 5.1 U2. I want to build Windows Server 2012 R2 Domain Controller, XenApp 7.5 and XenDesktop 7.5. I also plan to install PVS 7.1 if possible. So I would like to know now how many VMs can I get?
thanks in advance!