Re: how would you build it

On Tue, 3/17/2026 6:15 AM, John wrote:
> what hardware and components would you choose for your build if you
> intended to use it to host only multiple virtual machines?
> 
> These days, I worry about computer security and the creepy push of
> businesses extending AI into even simple tasks such as notepad.  Most
> of my existing gear works very well for what I do, but I'm thinking
> that it may be time to upgrade it.  If I do so, one direction would be
> to build a pc that would use some type of basic OS and host mullitple
> VMs on it tailored to the software I want to use.  My uses would be
> basic productivity software such as a spreadsheet, a basic text
> processor like Notepad, an email client, a web browser and RPG games
> like Baldur's Gate and its ilk.
> 
> The host OS will likely be some variant of Linux.  I will use
> VirtualBox for the virtual machines.  The guest VMs would be Microsoft,
> Linux and maybe Android.
> 
> In my questions below, I ask about the minimum because I want to know
> what I should consider as a starting point.
> 
> 1.  Given that scenario, what should be the minimum CPU speed?  My
> preferred brand is AMD.
> 2.  What should be the minimum amount of RAM?  I'm not expecting to run
> multiple VMs at the same time.
> 3.  To what extent is the choice of graphics (an integrated CPU or
> standalone, discrete graphics card) affected since any specialty
> graphics software will be installed in the VM, not on the host machine
> itself?
> 4.  What would be the strategy for the type, size and number of storage
> devices?  Off the top of my head, I expect to use hard drives for
> storing my data, but there are other types of devices such as USB, SSD,
> NVME (sp?), CD, DVD etc.

VMs need RAM.

Microsoft   W7 2GB    W10 4GB    W11 4GB   (minimums to be practical)
Linux       3GB                            (varies but to be practical, that is the minimum)
Android     Not tried this, will guess 4GB

Win98 and WinXP could be run in 256MB and 512MB, older OSes are lightweight.
I still keep a Win98 for running an Acrobat Distiller (makes "obsolete" PDFs)

*******

For graphics, you have to assume you'll never get "GPU passthru" working.
This likely requires two monitors, if you could manage it (two GPUs,
VM session uses second monitor).

With graphics missing, a 4.5GHz to 5GHz CPU helps.
In one isolated case, I watched in a Linux OS while some graphics
operation caused four cores to rail. I have no idea what it thought it
was doing :-) It used to be that graphics might rail one core, during
some MESA fallback 3D activity.

*******

If it wasn't for the graphics not being accelerated, you could have
used a slower CPU (like a ten year old one).

With an 8 core processor, you could have two cores for the Host,
and two cores for each Guest.

*******

RAM is really expensive right now. 16GB would cover a Host and three Guests.

I would not call it "my VM machine" at that level, but never the less,
that would be enough.

You could attempt to run the computer with a Celeron with just
the one core, but we're trying to be practical here, and we want
the machine to at least run Firefox worth a darn. You could run
on four cores if you wanted.

But really, if shooting money into the PC space right now,
and having an imbalanced system where most of the money goes
into RAM (and the motherboard), "you might as well have a CPU" :-)

My machine:

5700G  (had to turn iGPU off, due to a weird seemingly motherboard BIOS bug)
Lots more RAM than above

GTX1650 video  (considered low end, like my GTX1050 and my GT1030 in the other room)
               (if video unaccelerated for VMs, buying a 5090 won't help)

SSD 535MB/sec SATA for storage   VMs take space
   W10-1903.7z  6GB    (13GB decompressed and placed on RAMDrive)
   LM222X.7z    4GB    (11GB decompressed and placed on RAMDrive)
   MACOSBigSur 20GB    (32GB decompressed, is on other machine, used once and stored)
   There is room for the first two on the RAMDrive at the same time.
   After a session, container can be recompressed and stored on SSD.

While Virtualbox has a tick box for "experimental 3D support" as some
sort of 3D passthru at the drawing level, that's not going to help
the other OSes, and I normally leave that off just because I don't
know whether anything can use that (properly) or not. But as an
experimenter, you can play with that. The "drivers" for the video
interface in VM-land, seem relatively pathetic, but remember that
they're giving you efficient frame buffer access. If you saw how
SoftWindows updated the frame buffer a pixel at a time, then you
should appreciate that the current video driver is offering
better than that. But if you were thinking Vulcan and OpenGL
and WebGL and sorts of other stuff are accelerated, then that
is unlikely to happen.

On WSL2/WSLg (which is also virtualization), the GLXGears demo runs
at 350 frames per second. When hardware accelerated, that number
could be 4000 to 20000 on a OS on native hardware. That's to give some
idea what some CPU power gives for graphics emulation. And that's enough.
That much is usable graphics for 2D work. Not enough for a 3D game
of course, under WSL2.

Plenty of mid-range processors will work, but try to do a bit better
on RAM if the opportunity presents itself. An N150 mini-PC just won't
have the legs for this, it will be "overcome" by the load. It's
going to take a 65W processor, and preferably one with some core count.

   Paul