Great, virtualisation is back on the table! That makes things much easier!
Yes, the M10 has 4 8GB GPUs, and because you’re running RDSH you would use 1 of those for each RDSH VM, totalling 4 VMs. Depending on the resource requirements of your Apps and how your users use the system, each 8GB RDSH VM would support approximately 20 - 25 concurrent users. This is an industry average, your mileage will vary + / - which is why you should definitely run a POC before making any firm design decisions.
VMware (vSphere) is top of the line, but it’s not cheap. For vGPU, you’ll need vSphere Enterprise Plus. This is why it’s important to understand the difference between Passthrough and vGPU and also understand your workload and how it will use the resources. If you were to use the M10, because of your workload and the fact the M10 is a Multi-GPU board, you’ll be assigning an 8GB GPU; does it matter if that GPU is Passthrough or vGPU? The answer is, it depends on the amount of flexibility and features you want from the system. If you just want to provide access to a GPU enabled RDSH VM and don’t need any additional features, then you can get away with Passthrough and Essentials licensing with the M10. If you were to use the T4 you would have to assign the whole T4 (due to not having VMware Enterprise Plus licensing), making them 16GB RDSH VMs, but you would need fewer of them to support your density. Does that make sense?
For any VMware deployment, you really should be using vCenter. Without it, administering your vSphere Hosts becomes really limited. For vGPU however, it’s a prerequisite, but if you’re only using Passthrough, then you can get away without it, but it’s not something I’d ever recommend.
Regarding your ML350 specs, which CPUs are you looking at using?
To get started for your POC, you’d be looking at something like this for each RDSH VM with an M10 running in either Passthrough or vGPU:
SSD / All Flash Storage
That’s 128GB RAM total, leaving the rest for the Hypervisor, and you’ll be able to run 4 of those per ML350.
If you were to go down the T4 in Passthrough route, then you’d be looking at a scaled up version of the above with something like this:
SSD / All Flash Storage
In theory, you should need less of them as they’ll support a higher user density, and you’d tailor the vCPUs and RAM based on the POC results. If you were to use vGPU with the T4, then you’d be looking at the same specs as with the M10 but the T4 running as 8GB and supporting 2 VMs.
Those specs are not definitive, and the final specs will be based on your POC results.
If your ML350 is spec’d highly enough it will manage the 90 users (and above) without issue. But remember you should be providing N+1. If anything fails, you’ll impact a large percentage of users.
Depending on your final configuration, you’ll need a combination of the following:
vSphere Essentials / Enterprise Plus
Windows Server Standard
If you’re running Passthrough and have no intention of ever wanting vGPU, you can look at other Quadro GPUs and not pay any vGPU licensing. Because we’re now using virtualisation, we can have multiple GPUs in the same physical host (whereas with bare-metal, we can’t). You can now look at multiple Quadro P4000 or Quadro RTX4000 as these are single slot 8GB GPUs. You can run these in Passthrough and there is no NVIDIA licensing, however, these are still a bit much for just RDSH workloads, but you wouldn’t use anything smaller.
If you wanted to use the M10 or T4, you would be looking at vApps licensing (regardless of Passthrough or vGPU). With the exception of vCompute, all other vGPU licensing is per Concurrent User, so you’ll need 100 vApps licenses.
I hope that helps.
Overall, and despite all the configurable options, my recommendation remains the same as my first post. Don’t try and skimp on features and functionality if you can afford them. Use the T4s running 8A vGPU Profiles.