What is VMWare bad at? (What should i not use it for)

Question

Yesterday i decided to test a few programs and i decided to run a blizzard game. It ran so slowly that it was unplayable. It makes sense that accessing the GPU is slow (at least i think it may be) but is accessing all hardware slow? what is VMWare bad at and what should i not use it for?

I am using vmware player 3.0.0 build-203739 giving it 1536mb of ram.

Answer 1

VMware Player - Bad at making your own VM's!

VMware Workstation - Brilliant at most things.

With Workstation, it supports Direct X 9, and whilst it may not be as good as running directly on your host, it is still pretty decent and the latest version of Workstation (7) they have refined it further and the graphics are very good.

As Alex said, Disk I/O is also bad compared to a physical machine, but this can be dealt with by putting all the VM's on their own drive (not partition on same drive).

Personally, I use VM's for everything, I love it and think it is one of the best technologies!

Your title was "What should I not use it for". The answer really is nothing if you don't mind a slight delay when compared to running something natively and high end games. Apart from that, nothing!

With a bit of warning - If you are doing domain stuff, be careful of Snapshots and time synchronising... apart from that, Virtualisation is great!

Answer 2

Disk access speed is going to be lower; this can drastically affect performance. Also, the GPU, at the moment, handles rather badly when virtualized. The drivers are a major problem when it comes to virtualizing GPUs.

So, basically, any disk intensive app is going to suffer rather badly. Aloso, games and other GPU dependent apps are going to have problems.

Answer 3

With hardware assisted virtualization support obtained through AMD-V or Intel-VT capable processors and chipsets (motherboards), your VMWare virtual machines, which does support both technologies, will suffer less from performance issues. It's however still a reality that all your VMs can use is what you make available to them. And what you make available to them is limited by your computer computational power and available memory.

If there is one thing VMWare is limited at, regardless of how powerful your computer is, is support for OpenGL and DirectX technologies. While they are close to fully supported, performance is degraded considerably under a VM due to the fact VMWare cannot use your GPU directly, but instead needs to emulate its own, which then passes instructions to your GPU.

For anything else I can think of, provided you have either AMD-V or Intel VT capable processors and motherboards (and the technology is enabled in the BIOS), you are only limited by your computer resources. Theoretically, data intensive tasks can be running parallel on both the host and client machines without any significant loss of performance if you had enough resources in your machine.

Many VMWare servers employ multiprocessors, dedicated hard drives and copious amounts of RAM to enable exactly the sharing of VMs across corporate networks while still allowing for business-required performance levels.

Answer 4

As others have stated, VMWare is slow at using graphics functionalities and hard drive access. It can do these things, but it will take a performance hit, so you may want to rethink virtualizing things like a gaming machine, or a database server.

In addition, (as far as I know) VMWare can't present special hardware to the VM. It gives a standard set of virtual hardware to all VMs, which is great for being able to move VMs from one physical box to another. However, if you have a special piece of hardware on a PCI slot, VMWare will not be able to give it to a VM. If you need to do this, you should look at Xen.

Of course, these needs are pretty rare, but I thought I'd mention it here in the interest of completeness.

Answer 5

you shouldn't use virtual machines for gaming (as you found out the hard way :).

IF you really run graphic intensive games virtualized, then use Sandboxie (which has become hugely popular recently with the Diablo 2 community, to trick the battle.net servers and connect multiple instances on one computer simultaneously).

Sandboxie is freeware.

however, to create more than one sandbox, you'll have to register the software, you'll get lifetime support/upgrades and may install the software on as many computers as you own.