Virtualization on older computer

MisterEd · 20 Jan 2022

I don't think it is enough to have 8GB RAM and installing a 64-bit OS. You also have the limitation of a old CPU with 2 cores and 4 threads. This computer is simply not powerful enough to do virtualization of an O/S beyond Windows XP. However, a better option is do a dual-boot with another OS.

ittiandro · 20 Jan 2022

Ref previous post to Bree. Increasing the RAM.
By looking at my system specs, It occurred to me that I have a 32-bits OS ( Windows 10) on a x64-based processor.Does it mean that I can increase the RAM to 8 GB? It would be great. If so, do I have to install a new -64 Bits OS ( Windows 10) or can still use the -32 bits Windows 10 ISO?

Thanks

Ittiandro

Thanks

Ittiandro

Bree · 20 Jan 2022

ittiandro said:

Ref previous post to Bree. Increasing the RAM.
By looking at my system specs, It occurred to me that I have a 32-bits OS ( Windows 10) on a x64-based processor.Does it mean that I can increase the RAM to 8 GB? It would be great. If so, do I have to install a new -64 Bits OS ( Windows 10) or can still use the -32 bits Windows 10 ISO?

A 32-bit OS can only address a maximum of 4GB, if you add more RAM it will still run, but won't be able to use more than 4GB. In addition, some of that 4GB address space (typically 1GB) will be 'hardware reserved' for accessing the video RAM, meaning the RAM available to the OS is reduced. While a 64-bit OS can map that above the 4GB address and leave more RAM available to the OS.

Bree said:

A 32-bit OS can only address a maximum of 4GB, that is the highest address possible using a 32-bit word. In practice a significant part of that 4GB address space will be used to map the video RAM into the 4GB address space, typically 1GB or more.

That will be shown in Task Manager as 'Hardware Reserved'. There is no point in installing more than 4GB RAM in a machine with a 32-bit OS, nothing above the 4GB maximum could ever be addressed. The usable installed RAM will be less than the 4GB theoretical maximum by the amount set aside as 'Hardware Reserved' so in practice only about 3GB is available for use.

With a 64-bit OS the theoretical amount of virtual address space is 2^64 bytes (16 exabytes). The video RAM can be mapped to appear above the installed RAM, with just a very small 'Hardware Reserved' (typically less than 100MB) for communication.

For comparison, here is what I got with two clean installs of W10 2004, one x86, the other x64. Both installs were on the same 4GB machine, System Two in my specs below.

x86 - total physical memory available for the OS or the user = 2.93GB, available RAM with Windows running 1.8GB.

...

x64 - total physical memory available tor the OS or the user = 3.93GB, available RAM with Windows running, 2.5GB.

32bit backup to 64bit os? - post #3

jimbo45 · 23 Jan 2022

MisterEd said:

I don't think it is enough to have 8GB RAM and installing a 64-bit OS. You also have the limitation of a old CPU with 2 cores and 4 threads. This computer is simply not powerful enough to do virtualization of an O/S beyond Windows XP. However, a better option is do a dual-boot with another OS.

Hi there

@MisterEd

Not true

Running W11 on an 8GB on HP envy laptop with only 8GB RAM - using Linux KVM as host -- Windows 11 VM allocated 4GB and 2vCPU's. Response is almost as good as running W11 native on this laptop. In fact the system dosn't even pass Windows 11 eligibility check -- although it's an intel i5 core gen 6 processor.

VM's reside on external SSD connected to Host via USB3->SATA adapter.

Obviously more resources better but don't discount older laptops.

VM config

Virtualization on older computer-screenshot_20220123_163409.png

W11 update

Virtualization on older computer-screenshot_20220123_163558.png

Choice of VM at boot

Virtualization on older computer-screenshot_20220123_143420.png

I have 2 vm's on the laptop which I can boot via single VM config : a W10 and a W11 VM - not concurrently though !! as I've created the VM's on physical vhdx files. Convenience though of only needing 1 VM definition and being able to boot either.

Cheers
jimbo