VMWare vCenter Converter StandAlone 5.0 Slow Transfer Rate

VMware vCenter Converter Standalone LogoVMWare by default enables SSL encryption during the Physical to Virtual (P2V) and Virtual to Virtual (V2V) conversion process.  This has the effect of bringing the transfer rate to a crawl of as low as 200kbs instead of the expected 40mbs or better.

The problem is a VMware proprietary protocol called NFC that is used to create the source image and encrypt the data during the transfer process.

The SSL feature of the NFC VMware proprietary protocol can be disabled in a file called:


located in one of the following places depending on the Operating System:

Windows Vista, Windows 7, Windows 2008
%ALLUSERSPROFILE%\VMware\VMware vCenter Converter Standalone

Windows XP, Windows 2003, Windows 2000
%ALLUSERSPROFILE%\Application Data\VMware\VMware vCenter Converter Standalone

Find this section of code and change the highlighted TRUE to FALSE.

<!– Delay is specified in milliseconds, -1 denotes the default.


Should be:


It is CRITICAL that the “VMware vCenter Converter Standalone Worker” Service be restarted.  DO NOT FORGET THIS STEP!





  1. Solved my issue with a Windows 2003 server P2V, version 5 converter to a QNAP NAS. Very usefull! Thanks.

  2. Daniel Feiler says:

    Thank you for this information. It solved my problem doing V2V (ESXi 4.1 to ESXi 5.1) converting / copying, using standalone converter 5.01. The performance increases easily 10 to 20 times. (Before setting the parameter to false, I had 3% to 5% network load on a 1 GBit/s after setting the parmeter to false it was 67% to 99% load. 67% are the lowest peek. Average load was 87%

  3. Thank you, that’s better.

  4. Wanted to say thanks for this. Same scenario. V2V Throughput was below 200k and now it’s rocking.

  5. Tu Holmes says:

    This was excellent information… Always wondered why it was so slow… this quick change made my P2Vs scream.


  6. Saved the day – transfer was originally going to take 11+ hours
    With this hint – under 45 minutes


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