Not really a request; just a thought.
How about an option to delegate how much memory to dedicate. Kind of like Photoshop where you can set a fixed percent. Again, like PS, designate a scratch disk in the preferences so you could push to an SSD partition.
I don't know if this would help tweak/speed things up or not.
IMatch dynamically allocates memory as needed. Photoshop is a well-known memory hog and now seems to require a gig just to load RAW...
IMatch usually requires between 300 and 600 MB RAM, depending on the size of the database and how many objects it needs to cache.
It only requires larger amounts of memory to pre-cache files for the slide show and the Viewer, and here it allocates up to 3 GB of RAM, depending on the amount of free memory available. IMatch also cooperates with the memory manager in IMatch and frees memory or swaps if needed by other applications.
Photoshop just blocks 25%, 50% or more of the RAM in the computer and never lets go, not even when other apps need it. Adobe applications are not written to be cooperative. Hence the "how much memory can I use" setting in Photoshop, to limit it's memory hunger. Not even a web/database server capable of handling thousands of concurrent users needs as much memory as Photoshop does ;)
PS.: IMatch reports it's memory usage (current and peak) in the log file.