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We recently moved a web site from an old windows 2003 machine to a windows 2008 machine. This web site loaded content over a network share into the web site (TBH this is a rubbish idea that we plan to be rid of once we get around to it).

We noticed once the sites were deployed onto the new hardware that we were getting lots of:

The network BIOS command limit has been reached

Upon investigation we realised that one of the old sys admins had set the MaxCmds registry setting to it's maximum value on the 2003 machine. So the 2003 machine had 65535 connections and the new one only had 50. Problem solved.

Got me thinking though, the article on this recommend a setting of 2048 (not 65535 as the old sys admin had set).

What are the downsides to having such a large MaxCmds setting??

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up vote 2 down vote accepted

The only downside is the additional memory that it would require.

You should reserve about 512mb of RAM for every 12000 MaxCmds that you allow.
However, it would be a good idea to monitor the server's memory usage to make sure it isn't paging too much. If it is, you should reduce the MaxCmds in small increments until it is stable.

There's more information, including some algorithms to figure out the appropriate MaxCmds value for your situation, here:

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that's exactly what I'm after thanks. Will award the bounty in 24 hours (when it lets me). – Liam Feb 4 '14 at 10:43

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