Hyper-V vs. VMware ESX

The Tech Target website has published a comparison article that compares the pricing of Hyper-V and WMware and the benefits consumers have with each of those Windows virtualization technologies.

“Microsoft touts Hyper-V as a lower-priced virtualization option than VMware’s ESXi, but for straight server consolidation, it’s unclear whether Hyper-V is that much cheaper than VMware because of Hyper-V’s system requirements and lower consolidation ratios”, writes Bridget Botelho.
It is true that VMware has higher consolidation ratios than Hyper-V. Another benefit of WMware is taht their ESXi runs on older CPU models. At the same time Hyper-V requires consumers and businesses to buy latest hardware, which means the most expensive one. Hyper-V also requires more RAM per Virtual Machine than VMware’s solution.

The Tech Target author’s explains that decision makers in IT departments have to be careful when they calculate their costs and return of investment when they need to use virtualization for server consolidation. The technology media says that the any comparison chart of the cost per Virtual Machine between Microsoft’s Hyper-V and VMware’s ESXi is not “entirely straightforward”, and “there are several factors to consider”.

Cost Comparison

According to the cost comparison made by the Tech Target, both Microsoft Hyper-V and VMware ESXi 3.5 boast a $0 price tag and provide a certain amount of functionality out of the box, at least on paper.

VMware’s has a free version of ESXi and its users get a fully featured hypervisor with no limitations on CPU, memory, storage or networking.

Microsoft offers a free download of Hyper-V. Its users however need to upgrade to the full Windows Server 2008 edition, and to purchase System Center, which is the full version of the virtualization software to have access to get all management features.

VMware advertisers ESXi Server 3.5 as a solution which can be installed on servers with up to 32 processors and each the server processors may contain up to six cores. This means that a single server can supports up to 256 GB of RAM, and up to128 Virtual Machines are supposed to run on the host server.

Microsoft says that Hyper-V supports up to 24 processors on a server,  and the user can host up to 192 VMs on ther server.

However as it always happens in real life (We all have experience with car dealers ) the support numbers set by producers have less to do with the reality.
A realistic consolidation ratio for VMware’s ESX is 1 – 3 VMs per processor. This means that a 2-socket, Dual-Core server could support between 4 and 12 Virtual Machines, depending of the workload and the type of server.

Pricing out Hyper-V and ESX Servers

The Tеch Target’s makes a comparison by taking a real-world workload and price it out for both Hyper-V and WmWware’s ESX. The media compares the cost of 30 virtual machines on three dual-processor hosts.

In VMware this means to buy the Infrastructure 3 Foundation Acceleration Kit, that supports up to 6 processors and offers management via vCenter Server Foundation. The list price without support is $2,995. If we need to add the lowest level of support for 1 year (Gold license ), this increases the price to $3,624.

Microsoft offers free download for Hyper-V as a standalone virtualization solution. According to system engineers and administrators however Microsoft’s licensing requirements make very hard the direct comparison of Hyper-V with ESX.

Although users can run Hyper-V without Windows Server 2008 is, the Microsoft’s hypervisor is integrated with Windows. This means that any Hyper-V users has to run Windows OS or SuSe (Microsoft only supports Windows and SUSE Linux Enterprise Server 10 as guest Operating Systems). So if someone wants to use Hyper-V with Windows, they still need to install 64-bit version of the Windows Server 2008 OS. This brings the costs up.

When users use Hyper-V on Windows, they need licenses for the windows OS installed on Virtual Machines. The Tech Target quotes Rajiv Arunkundram, the Senior Product Manager of Windows Server Marketing at Microsoft who says that “It should be noted that any virtualization platform acessing Windows, Including VMware, requires CALs”. CAL refers to “Client Access Licenses”, Microsoft’s name for the licenses issued for users and devices that have to access a any edition of Windows Server. This requirement increases the cost of Hyper-V’s use.

If Windows users want to run 30 Virtual Machines on 3 Dual-Processor servers they have to spend on CALs. This means 30 CAL licenses. Microsoft sells through their own website Windows Server 2008 Standard Edition, Hyper-V, technical support and 10 CALs for $1,999.

So if we have 3 servers 2xCPU each, and if they run 30 VMs, this will cost $3,624 with VMware ESXi with the Foundation Acceleration Kit is $3,624, or $4,620 with Foundation Edition licenses (support included). If we are about to use Hyper-V, the cost would be $1,999.

These numbers show Hyper-V / Windows Server 2008 Standard Edition as less expensive solution that than VMware’s basic options. But there are other cost that apply. Virtual Machines require memory, CPU upgrades, so the payments for virtualization technology licensing is only the beginning.

Vmware says that ESX offers better memory utilization and this gives it an advantage over Hyper-V.

It is true that Hyper-V based Virtual Machines use more RAM than those based on VMware ESX. VMware’s recommendation to system administrators is to allocate 1GB – 2 GB of RAM for each Virtual Machine, depending on the workload. Microsoft recommends more than 2 GB of RAM to be allocated for each Hyper-V based VM.

With Microsoft’s Hyper-V users need 2 GB of locked RAM for each Virtual Machine. VMware however has a RAM management technology which enables its ESX to reclaim any physical memory, that is not in use and makes possible other VMs to use it.

To see comparison between Hyper-V and VMware read Gabe’s Virtual World blog. Original article of Tech Target “Hyper-V vs. VMware: Which is cheaper?” can be found here.