vSphere 5 introduces a whole new licensing method (and gets rid of “Advanced”). Previously you paid per CPU and were limited to how many cores your CPUs could have (6-cores except for Advanced and Enterprise Plus) and how much RAM your host could hold (256GB unless you had Enterprise Plus which was capped at 1TB). You were also limited to 4-vCPUs in a VM unless you had Enterprise Plus when you could allocate 8 vCPUs.
Now, VMware is charging per CPU with no physical core or RAM limitation. However, you can only allocate 8-vCPUs (except Entperprise Plus which gets up to 32 vCPUs) and the total memory you can allocate to VMs is now restricted based on licensing.
The RAM limit is a set amount based on the licensing level and # of CPUs – but you can pool the resources.
For example, the most common level sold will be Essentials Plus. This will include up to 3 hosts with up to 6 CPUs total (limited of 2CPUs per host for Essentials Plus). The vRAM limit is 24GB per CPU for a total pool of 144GB (24GB * 2 CPUs * 3 hosts). There is not a hard limit to the # of VMs you can create but you cannot allocate more than 144GB of RAM between all of the VMs.
The main customers affected by this would be those trying to cram large work needs into an Essentials Plus license by getting the largest 3 servers they can.
Previously (v4.1) your max RAM allocated was 256GB per server (without over-committing) or 756GB total for an Essentials Plus license. Now you’re limited to 144GB total.
This won’t affect the intended target audience for Essentials Plus, but it will crimp the style of anyone using the “build it bigger” approach.
Which also means there is a new answer to the “How much RAM can a VM have” question. It used to be 255GB, now it depends on licensing level and how many licenses you purchased – 144GB, 192GB (Standard kit), 256GB (Enterprise or Ent+ kits) or 1TB if you have Standard, Enterprise or Ent+ with enough licenses (44 Standard, 32 Ent or Ent+)
Also, it looks like Advanced is gone for good, Standard and the Essentials don’t get anything special and the best new features are only in Ent+ (Profile Storage, Auto deploy, Storage DRS)
Also in case you were wondering, current v4.1 Advanced licenses get a free upgrade to v5 Enterprise.