pro tools 11 and mac pro

i have pt 10 and 11, my mac is

early 2009

xeon 2.66 quad core

16gb ram 1066

ssd

geforce gt 120

and Yosemite



my pt 10 running really fine in performance and looks smooth, but pt 11.3.1 running really "laggy" , the sysem usage looks fine and near the 25% in pretty big sessions but the workspace, the clock, the faders, really laggy and looks like the pc is slowly,, but everything ok. anyone know that problem?