New hosts, what CPU to choose?

[HendersonD]

Our current ESXi hosts are 5 years old and will be replaced in the next few months. We plan on purchasing new rack mounts servers from either HPE or Dell

1. Two new servers for server virtualization - we run about 40 VMs with 35 of them running Windows Server 2012 R2 and the rest Linux. Mix of VMs with heavier use like SQL2014 and many lighter load VMs
2. Three new servers for VDI - we have about 160 Win7 desktops spun up, each with one vCPU. With the new servers we will be jumping to Win10, 2vCPUs per desktop, and also have nVidia Tesla M10 cards installed to give some GPU horsepower to each desktop.

The newest servers come with two Intel's Skylake processors installed. These processors have 4 different ranges, Platinum, Gold, Silver, and Bronze, we are focusing on the Gold range and have narrowed it down to 4 choices

Processor	Cores	Speed (GHz)	Suggested Retail Price	Total cores for server virtualization	Total cores for desktop virtualization
6132	14	2.6	$2,111	56	84
6140	18	2.3	$2,445	72	108
6142	16	2.6	$2,946	64	96
6148	20	2.4	$3,072	80	120

These servers will have plenty of RAM, 10Gbe connections, and are backed by a Nimble All Flash Array

Any suggestion on which CPU to choose?

[jasnyder]

You're looking at 10 VMs/proc on the server side and 26 VMs/proc on the VDI side.  I don't think you can go wrong with any of these choices, but I'd probably go for more cores over clock speed with all things being equal, so the middle 2 options seem fine.

Be sure to account for failover capacity.  I don't think CPU is going to be your constraining factor (it's usually memory or storage I/O, unless you hit high consolidation ratios or have intense compute jobs running), but if you lose a host, make sure you can run everything on the remaining hosts.  Also understand that if you lose a host you're losing either 50% of your server environment or 33% of your VDI environment while waiting for a reboot to happen on the other nodes.  The only way to compensate for that is more hosts which brings its own problems (like extra licensing, extra hardware costs, extra power/cooling costs, etc.), so it's not necessary something to worry about, but just to be aware of.

[HendersonD]

I currently have

• 3 hosts for server virtualization x 2 processors per host x 8 cores per processor = 48 cores
• 4 hosts for VDI x 2 processors per host x 8 cores per processor = 64 cores

Of course these are 5 years old Intel E5-2650 processors running at 2GHz. The new processors will be way faster no matter what I pick. We did decide to drop from 3 to 2 hosts on the server side and 4 to 3 hosts on the VDI side. Even if I lost a host on either side things should be fine. It does make me a little nervous with only two hosts on the server side. If one has an issue and goes down, I am sitting with one host in production. I do have a DR site that will also have 2 new hosts so worst case I can fail over there.

I think the decision here falls on the VDI side since I am jumping to 2 vCPUs per Win10 desktop rather than using just 1 vCPU for Win7. I am leaning towards the 6142 which runs at the highest clock rate of the 4. We will be running Autodesk Inventor and Revit on these desktops, both of which are single threaded. The faster clock rate will help with these and I think the core count on the 6142 is adequate