I gave up on tring to do video in Sonar Pro X1 expanded,I just do all my sounds tracks in sonar,then sync to another computer running Sony VEGAS.
I run a 32gig,ddr3 mem, SSD 160gb hd,2 Tb external dual Intel I7
a motu 828mk3,motu 128,motu mtpAv tascam us1641,edirol 25ex,2 vsr880 HD recorders.
and like you a ton of outboard gear(my 40 yr collection...lol)
I found even with all this video just sucked the primary computer to death...sonor is a massive program and we use live musicians..so there is not much loops and snipets.
The video computer is a 8gb Acer quad core...does video fine(and the 2nd computer you can pick up for next to nothing)sonor is trying to fill to many function in order to appeal to the largest audiance...they should stick to what they used to be good at ...SOUND...I guess roland is pushing the buttons now.get it out and fix it later and charge as a upgrade not a bug fix update.I love the new x1 expanded but many do not realize the hardware required to really take advantage of it.most of the complaints I have read on here really stem from expecting this pro studio program to preform on shoe string budjet interfaces and computers.if you look into protools and avid to get this level of processing you would easyly be in the 20k+ dollar range,so just deicate your best computer to sonor ,sync or run a network for video.even with the earthnet running at 1000mb your still double the speed to avoid for latency.hope this helped out a bit.