I have a new system (specs in my signature). X1 Producer installed on SSD C: including all plug-ins. My project audio and exports are set to different (7200 RPM disk) drive to save space on C:drive. No partitions. Ton of drop outs since installed on new system, stable on last computer with one drive partitioned.
1) Should Sonar and all plug-ins and audio be stored on one drive?
2) Are there known problems with install on SSD card as opposed to standard disk drives?
Thought I would start with possible set-up before other possibilities up the chain. 

SSD should be no issue.
You DO NOT want your audio on the "C" drive.

Is the Audio drive a so called "Green" drive?

What model exactly is the audio drive?

T

no green drive  
7200 RPM 64MB cache 1TB (Seagate Barracuda ST1000DM003 1TB 7200 RPM 64MB Cache SATA 6.0Gb/s 3.5" Internal Hard Drive -Bare Drive)
I built the system to handle full HD video editing. it has performed well for video and Adobe.  

Check the drivers... be sure it's ASIO. 

I keep all my music on the C drive until I finish with it, then I move it to a storage drive.

I keep my samples on the storage drive. 

What version of Windows 7, i.e., Home or Pro? Home can only use 16GB.

Are you using USB 3.0 ports? 

Disable any other soundcards. You don't have a USB microphone, do you? 

it is ASIO driver. Mackie driver. Use Firewire not USB
I am using Windows Pro to utilize all my RAM. 
I will try disable onboard card no USB microphone. 

Ok,Here are somecommon problems with SSD drives,They stack in a tree format
and do not populate space the same as a normal  sata 7200 ,
Do not defrag them..you'll loose data and damage the drive
,anti-virus and maitenace programs that run on a schedule,will over run sectors.
turn them off.(check your ssd drive manufacture for stats) work off your ssd but place every thing else
on another 7200 drive
I run a 160gb SSD sata 2 ,no problems since I do not have it connected to the internet,and don't need the constant
maitenance and AV stealing resources.I use a usb key for updates but only for music software and not the constant
window security updates(not on line you don't need them)