everything 64 bit, producer, with an Emu 0404, processor is....... phenom II black edition I think. yeah i have done all the prelims. Ram usage is at 1.3gb idle going up to 1.5 with the project loaded. 5%cpu usage. I have run huge sessions with no problem for years with 4gb being more than enough.
 
I know w7 appears to use more ram than before, but from what i understand it preloads, then drops when you actually need more available.
 
tried hosting the project from both c:/ and secondary drive.
 
 
i was running similar sessions on my less powerful MBP last week (not with me right now), also with 4gb of ram.
I know I have seen this problem posted before, but cant find a record of any solution.
 
 
thanks for the response guys!

i think its the massive number of clips on a single track causing the problem. there are probably a few thousand after removing silence. a new track in the same project with a few clips seems to be responding fine. anyone know where the bottleneck is?

Are you using X3E? Have you defragged?
Merge the clips/bounce the track....Ta.

When you say that RAM usage is 1.5GB with the project loaded, is that total RAM usage including Windows, etc?  If so, then there's around 2.5GB free?   How about CPU usage both at project load and while trying to move a clip?
 

Ram usage is for the whole system, yes. A full 2.5 gigs free. 
 
 
CPU usage of just Sonar jumps from ~3% to 25% when moving  a clip. (33% system total)
On a separate track, with fewer clips, Sonar CPU usage jumps to just 10% and there is no delay in moving. 
 
 
I am obviously exceeding the max number of clips allowed on a track, but at a glance my system hardly seems stressed, so is this a Sonar limitiation. 
 
 
ill just come up with a workaround next one of these projects I do. 

Thousands of clips in a 1 hour 45 minute track is a little extreme. It does not exceed any limit within SONAR but may be a little difficult for this particular machine to handle. I can't imagine trying to run the project on the system drive. It is not clear how the "secondary drive" is attached to the PC. The project file may be larger than normal but have no information about it. Hopefully virus scanning has been turned off for the directories storing the project and audio data.