This happens when I have a Synth loaded, for example Kontakt (even without any loaded instrument without RAM consumption):
When I quit Sonar, it takes up about 30 seconds to fully discharge the RAM (visually, when the MIDI activity icon disappears from the taskbar).
Until Sonar does not unload completely from RAM, I can not run it again.
Can anyone tell me if there is any way to speed up this unloading?

Why close SONAR if you're just going to open it again? Wouldn't it make more sense to close the project and open a new one?

I side with the OP here. I often prefer to close Sonar completely just in case to get rid of anything that might be resident, lucky for me I rarely get these sort of issues. So if Sonar is taking ages to close then it's probably a good precaution.
 
Any 32 bit plugins in the project?
Have you tried disabling virus scanner?
Try updating your interfaces drivers and firmware in case transport is locking it up.
If you reset MIDI and audio in Sonar will it close quicker?
 
Ta.

I also usually close Sonar as well. I had a similar issue that i couldn't open Sonar again for roughly 15-30 seconds after i closed it unless physically ending it in task manager. Turns out my audio driver just doesn't know when how to let go of its beloved Sonar. After an update of my audio driver, iv yet to have the problem.

On a side-note to Mr. Anderton.. ( i totally thought of matrix Mr. Anderson.. im sorry).  It might just be like an OCD thing, i like things to "complete".. if i just close the project and open it within Sonar ill still "feel" like im in same project. I dunno how to explain lol
 

I discovered the problem: it is called ASIO4ALL. Once again.
Using other devices, the problem does not occur.
It is a high price I have paid for not investing in a Focusrite yet ... I think now is enough ...

I close and restart SONAR often, and is immediate. The OS is responsible for releasing memory, so with SONAR closed something else is still open that got "linked" to SONAR.

Wouldn't sonar stay in ram until the system needed those resources?

rogeriodec
This happens when I have a Synth loaded, for example Kontakt (even without any loaded instrument without RAM consumption):
When I quit Sonar, it takes up about 30 seconds to fully discharge the RAM (visually, when the MIDI activity icon disappears from the taskbar).
Until Sonar does not unload completely from RAM, I can not run it again.
Can anyone tell me if there is any way to speed up this unloading?

Is it any synth or Kontakt? It might be the synth itself that is taking time to unload. 

I find that if I close a project and open a new one, I consistently get 2 little icons on the top left of Sonar, instead of one. From experience, this tells me that Sonar is getting unstable - I've had this in X3 a well. I have also seen 3 of these icons after closing and re-opening. 3 icons tells me that the project is doomed to crash very shortly. So to avoid this weird thing, I'll exist and reopen for the best stability. I've never reported this as it seemed quirky and I can work around it, but I'm curious if others may have seen this?