Virtulization Server

I am wanting to set up a server to fun a bunch of vm's on.  I know I am going to need plenty of cpu and ram horsepower.  I was just trying to decide between ESXi 5.5 or Windows Server 2012 R2 with the HyperV role.  What are some of the pros and cons of each?  How well does HyperV handle Linux vm's?  I guess which would you think is the best Hypervisor to use.

i am gonna say esxi. HyperV i believe supports linux guests, but i have no personal experience with that. i have used HyperV for windows guests but am turning towards linux for many systems. my current server runs linux and the college i go to uses ESXi for all their hypervising. and they have a few windows systems. not many though

Hyper-V does support Linux VMs. There's a comprehensive table of supported distros and which features they support for each version of Hyper-V and the distro. Just click on the distro you prefer and it'll show you the table.

As a side note, Linux support is far better in Hyper-V 2012 than it was in Hyper-V 2008. But if you are using almost exclusively Linux VMs then I'd recommend just going with a VMware solution as it supports Linux better overall.

I have been leaning to ESXi, just wanted to see what you guys thought.  May give HyperV a try on my Win 8.1 machine.

I'd advise you use ESXI. If you are setting out to create a virtulization server, you should use a Type1 hypervisor (or baremetal hypervisor)

Type 1 are where the OS itself is just really an interaction layer between the hardware and guest OS's.

Type 2 (the ones that install within an OS (like Virtual Box and Hyper-V)) are the sort of thing used for testing and not really performance. This is because now for the virtulised OS (to get to the hardware) has to pass through more layers. Through the Virtulisation software, into the Host OS, then through the various layers until it reaches hardware. Which can increase response times and thus reduce overall performance.

A better representation of what I am trying to say. (Bear in mind in the above diagram the guest OS on type 2 hyper-v is technically sat above the application layer as the virtulisation software itself is an application)

Hyper-V actually is a Type I bare metal hypervisor. When you install the Hyper-V role, the server OS actually becomes a virtual machine in Hyper-V.

Ah, learn something new everyday. Did not know that, been along time since i've done anything with Windows Server.

Yeah it's easy to not be aware of that because it's entirely in the background and they barely even mention that it actually does that anywhere.

I personally have no experience with ESXI, but I can definitely reccommend Proxmox Virtual Environment. I have it running for fun on a server at home (I can post specs if you guys want) and I love it! Easy web interface to manage it, and you can configure everything under the shining sun, plus its Debian Linux based so you can modify it as you see fit.