Dr machine increase render time

Evening we have 4 slaves all same spec all same ram but 1
Seems to increase the render time of our animation by about 1 min
Any ideas?
Running max 2013 latest vray all pre calculated ir and lc
All unc paths etc etc
Only difference this is installed as workstation.

Any ideas as I have it out of our farm saves a min per frame
Thanks

why use DR for animation? it will be much more efficient to use backburner and send single frames to each box.

having said that, no idea why one of your machines would slow down DR… network congestion?

maybe not latest LAN driver for that pc?
maybe that pc running antivirus scan in background?

Cool thanks for replies will test the one failing is the it managers one
So dosent have anything untoward running
Will give backburner a go over the weekend coming