[fedora-virt] intel vt versus amd-v?

[Don Dutile]

Robert L Cochran wrote:
> 
> 
> On 06/05/2009 01:47 PM, Richard W.M. Jones wrote:
>> On Fri, Jun 05, 2009 at 11:57:14AM -0400, Robert P. J. Day wrote:
>>   
>>>    a friend wants to buy a server (probably dell) with HW virt support,
>>> and is wondering if there are any current clear advantages of intel
>>> over amd.  the only observation i had time to make was that, if one
>>> checks out entry-level servers from dell (ballpark $1000 cdn), the amd
>>> opteron systems appear to be somewhat less expensive than equivalent
>>> intel-based systems.
>>>
>>>    further thoughts?
>>>      
>>
>> The more recent Intel and AMD parts have extra virtualization features
>> which make virtualization more efficient -- primarily Intel Extended
>> Page Tables (EPT) and AMD Nested Page Tables (NPT).  So your friend
>> should look at the chips which support that, basically Intel Nehalem
>> and the quad-core AMD Opterons (previously known as Barcelona).
>>
>> If he wants to assign devices directly to guests, maybe look at Intel
>> VT-d
>> / AMD IOMMU.  Not used it myself.
>>
>> Rich.
>>
>>    
> What a shame...I don't have a Nehalem processor in my Dell Latitude
> E6400...I wonder if I can just buy the mobile version of a Nehalem chip
> and replace my P9500 with it...
> 
If you have a Dell E6400, your laptop has Intel EPT & Intel VT-d
(as does the E6500).
Make sure virtualization is turned on in the bios
(I think there's two virtualization switches -- one for CPU virtualization,
and one for IO (vt-d/iommu) virtualization).

- Don (happy owner of E6500... and the above reasons why I choose it.)

> [root at deafeng3 ~]# exit
> logout
> [rlc at deafeng3 ~]$ cat /proc/cpuinfo
> processor : 0
> vendor_id : GenuineIntel
> cpu family : 6
> model : 23
> model name : Intel(R) Core(TM)2 Duo CPU P9500 @ 2.53GHz
> stepping : 6
> cpu MHz : 800.000
> cache size : 6144 KB
> physical id : 0
> siblings : 2
> core id : 0
> cpu cores : 2
> apicid : 0
> initial apicid : 0
> fpu : yes
> fpu_exception : yes
> cpuid level : 10
> wp : yes
> flags : fpu vme de pse tsc msr pae mce cx8 apic mtrr pge mca cmov pat
> pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx lm
> constant_tsc arch_perfmon pebs bts rep_good pni dtes64 monitor ds_cpl
> vmx smx est tm2 ssse3 cx16 xtpr pdcm sse4_1 lahf_lm tpr_shadow vnmi
> flexpriority
> bogomips : 5054.28
> clflush size : 64
> cache_alignment : 64
> address sizes : 36 bits physical, 48 bits virtual
> power management:
> ....
> [processor 1 info duplicates above]
> ....
> 
> 
> Bob
> 
> 
> 
> 
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