VMware vSphere

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  • 1.  Poor XP Performance

    Posted Sep 15, 2011 08:37 PM

    Has anyone seen a problem where Windows XP/2003 VM CPU performance is measurably worse than Windows 2000 on newer Intel processors? I've seen this with ESXI 4.0, 4.1 and now 5.0. I've tried uniprocessor and multiprocessor HALs, I've converted existing machines, done fresh installs and always get the same result. I'm using a simple Perl script as my benchmark - all in-memory string handling. I'm seeing the problem on a Pentium Dual-Core E5400 and Quad-core Intel Xeon E5410 2.33GHz. On a Dual-core Intel Xeon 5150 2.6GHz or a Dual-core Opteron 2220 2.8GHz XP and 2000 produce identical results.

    I started looking into this when I benchmarked a real application and noticed it was slower on the faster processor.



  • 2.  RE: Poor XP Performance

    Posted Sep 15, 2011 08:46 PM

    Interesting,   We have noticed slower performance on all our new hosts as compared to our old hosts.   We have not been able to nail down what is going on yet.       I'd have to check if it is affecting Windows 2003 / XP more than 2008 / Win7 though.



  • 3.  RE: Poor XP Performance
    Best Answer

    Posted Sep 15, 2011 08:51 PM

    I suspect that your newer processors are using hardware-assisted virtualization, but binary translation actually performs better for these guests, due to frequent TPR accesses. This problem is often exacerbated by anti-virus software running in the guest.  However, Windows 2003 should not have this problem if you have installed Service Pack 1.

    Please see 'Scenario 2' on page 6 of http://www.vmware.com/files/pdf/perf-vsphere-monitor_modes.pdf.



  • 4.  RE: Poor XP Performance

    Posted Sep 15, 2011 08:58 PM

    Jim Mattson wrote:

    Windows 2003 should not have this problem if you have installed Service Pack 1.

    Oops.  That should be "Service Pack 2."



  • 5.  RE: Poor XP Performance

    Posted Sep 15, 2011 09:49 PM

    Wow thanks for the quick response. I haven't checked on Windows 2003 but for XP, overriding the virtualization setting to software only (BT + swMMU) improves performance considerably. Not quite matching Windows 2000  but within 115%. I'll have to try the other options.

    Thanks for the help! I've been spinning my wheels on this for weeks.



  • 6.  RE: Poor XP Performance

    Posted Sep 15, 2011 10:06 PM

    For Windows 2003, the preferred solution is to install Service Pack 2, if that is acceptable in your environment.  With Service Pack 2 installed, hardware-assisted virtualization should outperform binary translation.