[Novalug] 64bit vs 32bit

[Ivan]

Ivan Makfinsky wrote:
> novalug-request at calypso.tux.org wrote:
>> Message: 1
>> Date: Fri, 04 Apr 2008 12:03:28 -0400
>> From: William Warren <hescominsoon at emmanuelcomputerconsulting.com>
>> Subject: Re: [Novalug] 64bit vs 32bit (was FOSE wrapup)
>> To: novalug at calypso.tux.org
>> Message-ID: <47F65150.7010208 at emmanuelcomputerconsulting.com>
>> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>>
>> That's not a 64-bit issue..that's a VT issue which is different from 
>> 64 bit.
>>
>> Richard Rognlie wrote:
>>  
>>> On Fri, Apr 04, 2008 at 09:24:24AM -0400, Pete Nuwayser wrote:
>>>    
>>>> I agree with Greg:  a 64-bit OS will not run on 32-bit architecture,
>>>> but 32-bit OS will run on 64-bit architecture.
>>>>       
>>> And to further complicate matters, there are times when a 64bit CPU can
>>> not accept a 64bit OS.
>>>
>>> I ran into this with VMware. 
>>> Dell 1850 server.   64bit CPU.  64bit OS on the box.
>>>
>>> But I am unable to install a 64bit "guest" OS on the box due to the
>>> CPU lacking the "VT" (virtualization technology) flag.
>>>
>>> Had to get a 1950 to get the CPU upgrade...
>>>
>>>     
>>
>>  
In order to determine whether or not you can run a 64bit OS on a certain 
CPU, look for the following:

$ cat /proc/cpuinfo | grep flags
flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge 
mca cmov pat pse36 clflush mmx fxsr sse sse2 syscall nx mmxext 
~~~~lm~~~~~ 3dnowext 3dnow rep_good
flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge 
mca cmov pat pse36 clflush mmx fxsr sse sse2 syscall nx mmxext 
~~~~lm~~~~~ 3dnowext 3dnow rep_good

"lm" - Long mode, indicates the CPU is 64 bit capable.

- Ivan