memory question

What does VPC see of the physical memory in the host os?

For instance:

I have a machine with 8GB ram with a 32 bit host os. The host OS sees only 4
GB of the 8GB right?

If so what of the top 4GB does VPC see? If I want to try win7 64 bits can it
use the top 4 GB as it can see it?

Or do I make a thinking error here.

I want to test the win7 64 bits with higher mem, but don't want to install
it and lose the old OS...

thanks

>I have a machine with 8GB ram with a 32 bit host os. The host OS sees only 4
>GB of the 8GB right?

Correct. (if it's a client OS, a server sku may be able to address
more using PAE)

>If so what of the top 4GB does VPC see? If I want to try win7 64 bits can it
>use the top 4 GB as it can see it?

None. VPC only sees what the OS sees, and only about 3.7G max, even
on a 64-bit host OS. It only supports 32-bit guests.

>I want to test the win7 64 bits with higher mem, but don't want to install
>it and lose the old OS...

None of the VM solutions will be able to see the RAM that the OS can't
see.

--
Bob Comer


On Sat, 26 Sep 2009 08:03:01 -0700, Bas
<> wrote:

>What does VPC see of the physical memory in the host os?
>
>For instance:
>
>I have a machine with 8GB ram with a 32 bit host os. The host OS sees only 4
>GB of the 8GB right?
>
>If so what of the top 4GB does VPC see? If I want to try win7 64 bits can it
>use the top 4 GB as it can see it?
>
>Or do I make a thinking error here.
>
>I want to test the win7 64 bits with higher mem, but don't want to install
>it and lose the old OS...
>
>thanks

Thanks Bob!

From you answer I take it there is no 64 bit VPC version available if I were
able to find a 64 bit XP?

"Robert Comer" wrote:

> >I have a machine with 8GB ram with a 32 bit host os. The host OS sees only 4
> >GB of the 8GB right?
>
> Correct. (if it's a client OS, a server sku may be able to address
> more using PAE)
>
> >If so what of the top 4GB does VPC see? If I want to try win7 64 bits can it
> >use the top 4 GB as it can see it?
>
> None. VPC only sees what the OS sees, and only about 3.7G max, even
> on a 64-bit host OS. It only supports 32-bit guests.
>
> >I want to test the win7 64 bits with higher mem, but don't want to install
> >it and lose the old OS...
>
> None of the VM solutions will be able to see the RAM that the OS can't
> see.
>
> --
> Bob Comer
>
>
> On Sat, 26 Sep 2009 08:03:01 -0700, Bas
> <> wrote:
>
> >What does VPC see of the physical memory in the host os?
> >
> >For instance:
> >
> >I have a machine with 8GB ram with a 32 bit host os. The host OS sees only 4
> >GB of the 8GB right?
> >
> >If so what of the top 4GB does VPC see? If I want to try win7 64 bits can it
> >use the top 4 GB as it can see it?
> >
> >Or do I make a thinking error here.
> >
> >I want to test the win7 64 bits with higher mem, but don't want to install
> >it and lose the old OS...
> >
> >thanks
>

>Thanks Bob!

You're welcome.

>From you answer I take it there is no 64 bit VPC version available if I were
>able to find a 64 bit XP?

There's actually a 64-bit version of VPC to run on 64-bit hosts, but
it still only supports 32-bit guests. It's basically just 64-bit
drivers on the host, the rest is 32-bit.

There are other VM solutions that support 64-bit guests if that's what
you need. (like VMWare Workstation, VirtualBox, Hyper-V, ...)

You really out to think about Vista or Win7 64-bit instead of XP
64-bit no matter which VM solution you pick. XP 64-bit really didn't
work all that well and had poor driver support.

--
Bob Comer


On Sat, 26 Sep 2009 11:27:01 -0700, Bas
<> wrote:

>Thanks Bob!
>
>From you answer I take it there is no 64 bit VPC version available if I were
>able to find a 64 bit XP?
>
>"Robert Comer" wrote:
>
>> >I have a machine with 8GB ram with a 32 bit host os. The host OS sees only 4
>> >GB of the 8GB right?
>>
>> Correct. (if it's a client OS, a server sku may be able to address
>> more using PAE)
>>
>> >If so what of the top 4GB does VPC see? If I want to try win7 64 bits can it
>> >use the top 4 GB as it can see it?
>>
>> None. VPC only sees what the OS sees, and only about 3.7G max, even
>> on a 64-bit host OS. It only supports 32-bit guests.
>>
>> >I want to test the win7 64 bits with higher mem, but don't want to install
>> >it and lose the old OS...
>>
>> None of the VM solutions will be able to see the RAM that the OS can't
>> see.
>>
>> --
>> Bob Comer
>>
>>
>> On Sat, 26 Sep 2009 08:03:01 -0700, Bas
>> <> wrote:
>>
>> >What does VPC see of the physical memory in the host os?
>> >
>> >For instance:
>> >
>> >I have a machine with 8GB ram with a 32 bit host os. The host OS sees only 4
>> >GB of the 8GB right?
>> >
>> >If so what of the top 4GB does VPC see? If I want to try win7 64 bits can it
>> >use the top 4 GB as it can see it?
>> >
>> >Or do I make a thinking error here.
>> >
>> >I want to test the win7 64 bits with higher mem, but don't want to install
>> >it and lose the old OS...
>> >
>> >thanks
>>

Thanks Bob and Mark for your responses!

Right so if I understand correctly...

If I were to install Win7 64 bits like Bob suggests, it would see mem above
4GB and I could install VPC 64 bits and install any 32 bit guest OS in it?
And I could allocate 4GB to the guest as Win7 would use the rest above 4GB?

To go outside of the box : I could even install a server OS 32 bits if I
wanted to?

Thanks!

Bas

"Mark Rae [MVP]" wrote:

> "Bas" <> wrote in message
> news:006936F2-B855-4347-A4BF-...
>
> >> None. VPC only sees what the OS sees, and only about 3.7G max, even
> >> on a 64-bit host OS. It only supports 32-bit guests.
>
> > From your answer I take it there is no 64 bit VPC version available if I
> > were
> > able to find a 64 bit XP?
>
> Not quite... There is a version of VPC which includes specific drivers for
> 64-bit hosts - however, it is still a 32-bit application:
> http://vpc.visualwin.com/ngfaq.aspx#18
>
> VPC, in any incarnation, has never supported 64-bit guests.
>
>
> --
> Mark Rae
> ASP.NET MVP
> http://www.markrae.net
>
>

Thanks Mark!

This answered my questions, but raised one new one...

MS virtual server? Is this the new Hyper-V? For arguments sake: If I want to
install a server OS udner win7 I should install MS virtua server?

Bas

"Mark Rae [MVP]" wrote:

> "Bas" <> wrote in message
> news:63F62588-786D-40C8-ACA1-...
>
> >> Not quite... There is a version of VPC which includes specific drivers
> >> for
> >> 64-bit hosts - however, it is still a 32-bit application:
> >> http://vpc.visualwin.com/ngfaq.aspx#18
> >>
> >> VPC, in any incarnation, has never supported 64-bit guests.
> >
> > If I were to install 64-bit Win7 like Bob suggests, it would see memory
> > above
> > 4GB
>
> Yes.
>
>
> > and I could install the version of VPC for 64-bit hosts
>
> Yes.
>
>
> > and install any 32-bit guest OS in it?
>
> Pretty much. Bear in mind that only a handful of guest OS are actually
> supported by Microsoft, though most work perfectly well. That said, it can
> be a bit of a fight to install some distros of Linux, though...
>
>
> > And I could allocate 4GB to the guest as Win7 would use the rest above
> > 4GB?
>
> The concept of "above" and "below" is not really meaningful with 64-bit OS.
> Remember that each OS has a minimum amount of memory required just to get it
> to boot and a recommended amount of memory which it needs to run acceptably.
> This applies equally to your host and your guests. If you have 8GB on your
> host and launch a virtual machine to which you have allocated 4GB, that will
> leave 4GB for the host. If you then launch another virtual machine to which
> you have allocated 2GB RAM, that will leave only 2GB for the host - it's as
> mathematically simple as that. If you then tried to launch a virtual machine
> to which you had allocated 4GB RAM, VPC would tell you that there wasn't
> enough memory available. It's also important to remember that VPC is just an
> application running on your host machine and has to fight for resources with
> all of the other applications running on your host machine, so make sure you
> don't cripple your host by running too many virtual machines
> simultaneously...
>
>
> > To go outside of the box : I could even install a 32-bit server OS if I
> > wanted to?
>
> You could, though you might prefer to use Microsoft Virtual Server for
> that...
>
>
> --
> Mark Rae
> ASP.NET MVP
> http://www.markrae.net
>
>

>MS virtual server? Is this the new Hyper-V?

No, it's an older product from Microsoft.

>For arguments sake: If I want to
>install a server OS udner win7 I should install MS virtua server?

Win7 blocks the install of Virtual Server for one thing (there are
workarounds, but it's not supported), but it all depends on what you
want to do with the VM's. If it's a server OS that is just going to
sit in the background doing some particular task without much user
interaction with the desktop, then Virtual Server is good for that,
but if there's a lot of interaction with the desktop, then VPC might
be a better fit because it's designed for a user based desktop
environment.

So in other words when running a server OS, a traditional server task
it's better under Virtual Server (or the newer Hyper-V), but for
testing and development, VPC is better.

--
Bob Comer



On Sun, 27 Sep 2009 04:24:01 -0700, Bas
<> wrote:

>Thanks Mark!
>
>This answered my questions, but raised one new one...
>
>MS virtual server? Is this the new Hyper-V? For arguments sake: If I want to
>install a server OS udner win7 I should install MS virtua server?
>
>Bas
>
>"Mark Rae [MVP]" wrote:
>
>> "Bas" <> wrote in message
>> news:63F62588-786D-40C8-ACA1-...
>>
>> >> Not quite... There is a version of VPC which includes specific drivers
>> >> for
>> >> 64-bit hosts - however, it is still a 32-bit application:
>> >> http://vpc.visualwin.com/ngfaq.aspx#18
>> >>
>> >> VPC, in any incarnation, has never supported 64-bit guests.
>> >
>> > If I were to install 64-bit Win7 like Bob suggests, it would see memory
>> > above
>> > 4GB
>>
>> Yes.
>>
>>
>> > and I could install the version of VPC for 64-bit hosts
>>
>> Yes.
>>
>>
>> > and install any 32-bit guest OS in it?
>>
>> Pretty much. Bear in mind that only a handful of guest OS are actually
>> supported by Microsoft, though most work perfectly well. That said, it can
>> be a bit of a fight to install some distros of Linux, though...
>>
>>
>> > And I could allocate 4GB to the guest as Win7 would use the rest above
>> > 4GB?
>>
>> The concept of "above" and "below" is not really meaningful with 64-bit OS.
>> Remember that each OS has a minimum amount of memory required just to get it
>> to boot and a recommended amount of memory which it needs to run acceptably.
>> This applies equally to your host and your guests. If you have 8GB on your
>> host and launch a virtual machine to which you have allocated 4GB, that will
>> leave 4GB for the host. If you then launch another virtual machine to which
>> you have allocated 2GB RAM, that will leave only 2GB for the host - it's as
>> mathematically simple as that. If you then tried to launch a virtual machine
>> to which you had allocated 4GB RAM, VPC would tell you that there wasn't
>> enough memory available. It's also important to remember that VPC is just an
>> application running on your host machine and has to fight for resources with
>> all of the other applications running on your host machine, so make sure you
>> don't cripple your host by running too many virtual machines
>> simultaneously...
>>
>>
>> > To go outside of the box : I could even install a 32-bit server OS if I
>> > wanted to?
>>
>> You could, though you might prefer to use Microsoft Virtual Server for
>> that...
>>
>>
>> --
>> Mark Rae
>> ASP.NET MVP
>> http://www.markrae.net
>>
>>

Bas wrote:
> Thanks Mark!
>
> This answered my questions, but raised one new one...
>
> MS virtual server? Is this the new Hyper-V? For arguments sake: If I want to
> install a server OS under win7 I should install MS virtual server?

It is possible to run a server OS under Virtual PC 2007, or VPC7 on Win7, bit
most are not supported.

If you want to use a server vitualization product:

Hyper-V must be installed on the hardware. You cannot have Windows 7 as your
host OS is you are using Hyper-V. Hyper-V requires a machine with hardware
virtualization.

OTOH, Virtual Server 2005 runs under a host OS, like Virtual PC, except that it
runs as a service. Server 2005 is not supported under Window 7, though you will
be able to install it if you jump through hoops. See for example

<http://social.technet.microsoft.com/Forums/en-US/w7itprovirt/thread/a98e77b7-95d4-444f-8dbc-630c98074436>

--
David Wilkinson
Visual C++ MVP

Thanks all!

I guess VPC is the tool for me then!

Bas

"Mark Rae [MVP]" wrote:

> "Bas" <> wrote in message
> news:F853BBC7-27EB-4F2F-AD6F-...
>
> > MS Virtual Server? Is this the new Hyper-V?
>
> http://tinyurl.com/yey9ybr
>
>
> --
> Mark Rae
> ASP.NET MVP
> http://www.markrae.net
>
>

ONe more question:

How does Virtual PC handle multiple cores?

Can you dedicate more than one core to a VM?

Bas

"Mark Rae [MVP]" wrote:

> "Bas" <> wrote in message
> news:F853BBC7-27EB-4F2F-AD6F-...
>
> > MS Virtual Server? Is this the new Hyper-V?
>
> http://tinyurl.com/yey9ybr
>
>
> --
> Mark Rae
> ASP.NET MVP
> http://www.markrae.net
>
>