Question : Problem: Intel Virtualization Technology Question

On all of Intel's newer chips they ship with a "Virtualization Technology Bit."  I understand that this helps virtual machines and the host OS's share hardware resources more efficently.

My question is if you are not running VMs what type of performance effect does it have on your machine when this is turned on? None? Can it actually degrade performance?

I cannot find any article mentioning this on Intel's site, they all talk about increasing performance but only when using virtualization.  I do run VMs on my desktops for testing purposes, but 90% of the time I do not.  I tend to believe that it could possible degrade performance on a machine if no virtualization is being done since Intel gives you an option to turn it on or off and it is always off by default.

Answer : Problem: Intel Virtualization Technology Question

As you can see from the VMWare paper referenced above, clearly VMWare does not benefit much from VT with a 64-bit client ==> but it does have a very notable performance difference when running a 32-bit OS (as does Virtual PC).

I did a few timing tests for a previous question:

XP Pro, SP3 on Virtual PC 2007, time clicking "Start" to the desktop welcome music:
=> With hardware acceleration:   30 seconds
=>  Without hardware acceleration:   44 seconds

XP Pro, SP3 on VMWare Workstation, time from clicking "Start this virtual machine" to the desktop welcome music:
=>  With hardware acceleration:   22 seconds
=>  Without hardware acceleration:  31 seconds

Vista Ultimate x64 on VMWare Workstation;  time from clicking "Start this virtual machine" to the Vista sound at the login screen:
=>  With hardware acceleration:   32 seconds
=>  Without hardware acceleration:  36 seconds

All of the above were repeated twice ... with the order I booted in switched, just to be sure there was no cached memory influencing the timings.   The timings were identical on every boot.    Finally, I booted to the BIOS and disabled VT and then repeated the Vista Ultimate x64 boot ... it still took 36 seconds and it still works perfectly.

These results support the VMWare paper's comment r.e. VT not helping much with an x64 OS ... but they clearly show that it's a major improvement with 32-bit guest OS's.