# VMWare relationship to physical CPU - 32 or 64 bit?

## jot1109

I've been using gentoo on 15+ servers for more than five years now, and it just rocks. Stage 1 installs, different CPUs (AMD, Intel, Via), 32 bit, 64 bit, i consider myself as an intermediate user.

Life was easy back then. Now, i'm running bagvapp's vmware applicance, i.e. a Gentoo System in a VMWare on Vista, and i feel pretty dumb - cannot even tell if my CHOST setting is correct or not. The vmware image is built as an i686 arch, and i wonder if converting it to something more recent will improve anything. I know changing CHOST is tricky, but it's just a VM image, so i can revert easily.

Now, my host CPU is a http://ark.intel.com/cpu.aspx?groupId=30783. According to the specs it has Intel(R) virtualization technology, 2 cores, and supports 64 bit. This is exactly the CPU that /proc/cpuinfo shows, so it's not an emulated VMWare CPU.

Rumour has it that VMWare prefers AMD (vs. Intel) code inside their VMWare. Can i convert my system from i686 to AMD 64 and it still runs because everything is virtually emulated? Should i use Intel 64 bit because there's less to interpret?

I'm aware of the 32/64 bit performance discussion, but what about 32/ 64 bit in a VMWare? Does it behave the same? I'm using VMWare Player, if that makes any difference.

Any insights gladly appreciated

----------

## Plague.CZ

As far as ia have tested (most of the main distros as images on windows machine for testing), the emulated CPU should be determined by configuration. After that all instructions are encapsulated in the emulator, so there is no real difference for the emulated system concerning a CPU. If course there is a big difference on the host-side, but that's another area.

----------

## Hu

 *jot1109 wrote:*   

> I've been using gentoo on 15+ servers for more than five years now, and it just rocks. Stage 1 installs, different CPUs (AMD, Intel, Via), 32 bit, 64 bit, i consider myself as an intermediate user.
> 
> Life was easy back then. Now, i'm running bagvapp's vmware applicance, i.e. a Gentoo System in a VMWare on Vista, and i feel pretty dumb - cannot even tell if my CHOST setting is correct or not. The vmware image is built as an i686 arch, and i wonder if converting it to something more recent will improve anything. I know changing CHOST is tricky, but it's just a VM image, so i can revert easily.
> 
> Now, my host CPU is a http://ark.intel.com/cpu.aspx?groupId=30783. According to the specs it has Intel(R) virtualization technology, 2 cores, and supports 64 bit. This is exactly the CPU that /proc/cpuinfo shows, so it's not an emulated VMWare CPU.
> ...

 

Your host CPU is capable of 64-bit support, so VMware can run a 64-bit guest, even if the host is 32-bit.  You can "convert" the guest from i686 to amd64, but be aware that in-place conversion from 32-bit to 64-bit is considered extremely difficult, and most people will advise you to reinstall.  It will be faster.  This caveat applies whether the CPU is physical or virtual.  The only reason to do an in-place conversion would be if you wanted to do it as a learning experience, and had a great deal of time to kill.

With regard to Intel 64 bit, beware that ia64 is a completely different architecture.  It is very likely that you have an em64t chip, which would use the amd64 profile if you wanted to use a 64-bit Gentoo.

Where did you see the rumour that VMware prefers AMD?

----------

